Service delivery to handed over user equipment (ue) using a software-defined networking (sdn) controller

ABSTRACT

In one embodiment, a method implemented in a virtual network function (VNF) manager for delivering of services to a roaming UE is disclosed. The method includes identifying a trigger condition for handing-over delivery of at least a subset of services from a radio interface of a source radio base station to a radio interface of a target radio base station. The method also includes transferring the subset of the services to the target radio base station through a route based on information from a software-defined networking (SDN) controller of a SDN system that includes the source radio base station and the target radio base station. The method further includes causing at least one VNF to be deployed on the target radio base station, the at least one VNF on the target radio base station being adapted to offer the subset of the services to the roaming UE.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is related to an application entitled “ProvidingServices to a Roaming User Equipment”, filed on Sep. 28, 2015.

FIELD OF INVENTION

The embodiments of the invention are related to the field of networking.More specifically, the embodiments of the invention relate to systems,methods, nodes, and computer programs for providing services to aroaming user equipment (UE) using a software-defined networking (SDN)controller.

BACKGROUND

An ongoing trend in the telecommunication industry is to “move networkfunctions into the cloud”, meaning that instead of using dedicated andspecialized (but expensive) processing hardware, to run thecorresponding network functions in generic data centers comprising bulksof general purpose (but cheap) processing hardware. These data centersmay even be owned and operated by a different company and the processingpower would be rented dynamically, depending on the need and the price.

With the ever increasing processing power of computing hardware, it alsobecomes possible to use the spare resources of network nodes to act asplatform for hosting more/other network functions. In this scenario thenetwork node would also act as a mini-datacenter.

The European Telecommunications Standards Institute (ETSI)standardization forum has recognized this trend to virtualize networkfunctions and is standardizing an architectural framework for networkfunction virtualization (NFV), see ETSI GS NFV004 V1.1.1 (dated March2016), and FIG. 1. Network Function Virtualization envisages theimplementation of network functions as software-only entities that runon the NFV Infrastructure (NFVI) 130. As such, four main domains areidentified in FIG. 1:

(1) Virtualized Network Functions (VNFs) 100, as the softwareimplementation of a network function which is capable of running on theNFVI.

(2) NFV Infrastructure (NFVI) 130, including the diversity of physicalresources and how these can be virtualized. NFVI supports the executionof the VNFs. The NFVI 130 comprises hardware resources 140, which areabstracted by a Virtualization Layer 150. The NFVI 130 offers VirtualCompute 160, Virtual Storage 170, and Virtual Network 180 resources tothe VNFs 110 hosted by the NFVI 130.

(3) VNF Manager 120, which covers the orchestration and management ofphysical and/or software resources (via a NFVI Manager 190) that supportthe infrastructure virtualization and the lifecycle management of VNFs.VNF Manager focuses on all virtualization-specific management tasksnecessary in the NFV framework.

(4) NFVI Manager 190, which covers the orchestration, management, andlifecycle management of physical and/or software resources that supportthe infrastructure virtualization.

The NFV framework enables dynamic instantiation and management of VNFinstances and the relationships between them regarding data, control,management, dependencies and other attributes.

When combining the concepts of network function virtualization with theconcept of using network nodes as platform for hosting such virtualizednetwork functions, the network node platform would be used as NFVI 130and a VNF manager 120 would dynamically deploy VNFs 110 onto the NFVI130.

The network nodes used as a host for VNFs may be the powerful servernodes controlling the communication networks. Since these powerfulservers are typically very few and located centrally, there is not muchdifference over using central data centers. An alternative approach isto utilize those network nodes that are widely geographicallydistributed and where the sheer number of nodes in the network offers ahuge collective processing power. The use of radio access network nodes(radio base stations (RBS) such as Node B (or referred to as NodeB),evolved Node B (or referred to as eNodeB), or base transceiver station(BTS)) are a promising candidate. The prime advantage of utilizing radiobase stations would be that the NFV can be located very close to thesubscriber, and by that minimize latency and reduce network basedtransmission bandwidth.

Latency is in particular an issue for specific types of sensors ofmachine-to-machine (M2M) communication and machine type communication(MTC). In order to keep MTC devices simple and cheap, but also in orderto save battery power in autarkic MTC devices, any processing needed forMTC is off-loaded into the network. However, some of the processingoff-loaded into the network is time critical, e.g. reaction on certainsensor measurements. For these applications it is critical to have theprocessing as close as possible to the MTC device.

Software-defined networking (SDN) is a network architecture that aims atdecoupling control plane functions from data plane functions such thatseparate apparatuses may be utilized for different functions. In the SDNarchitecture, network intelligence and states are logically centralized,and the underlying network infrastructure is abstracted from theapplications. As a result, networking may be simplified and newapplications become feasible. For example, network virtualization can beaccomplished by implementing it in a software application where thecontrol plane is separated from the data plane. Also, a networkadministrator of a SDN system may have programmable central control ofnetwork traffic without requiring physical access to the system'shardware devices. With these benefits, SDN architecture based systems(referred to as SDN systems or SDN networks exchangeably herein below)are gaining popularity among carriers and enterprises.

It is a challenge to utilize the SDN architecture including the radioaccess network nodes and virtualize network functions and deliverservices in an efficient way.

SUMMARY

Methods of delivering services to a roaming UE are disclosed. In oneembodiment, a method implemented in a virtual network function (VNF)manager and the services are offered by a set of VNFs hosted on a sourceradio base station and are delivered to the roaming UE via a radiointerface of the source radio base station, where the roaming UE is toroam from a radio coverage area of the source radio base station into aradio coverage area of a target radio base station. The method includesidentifying a trigger condition for handing-over delivery of at least asubset of the services from the radio interface of the source radio basestation to a radio interface of the target radio base station. Themethod also includes transferring the subset of the services to thetarget radio base station through a route based on information from asoftware-defined networking (SDN) controller of a SDN system thatincludes the source radio base station and the target radio basestation. The method further includes causing at least one VNF to bedeployed on the target radio base station, the at least one VNF on thetarget radio base station being adapted to offer the subset of theservices to the roaming UE.

Apparatus for delivering services to a roaming UE are disclosed. In oneembodiment, a virtual network function (VNF) manager is used for theservice deliver. The services are to be offered by a set of VNFs hostedon a source radio base station and are to be delivered to the roaming UEvia a radio interface of the source radio base station, where theroaming UE is to roam from a radio coverage area of the source radiobase station into a radio coverage area of a target radio base station.The VNF manager includes a processor and a non-transitorymachine-readable storage medium that coupled to the processor, and thenon-transitory machine-readable storage medium contains instructions,which when executed by the processor, cause the VNF manager to performoperations. The VNF manager identifies a trigger condition forhanding-over delivery of at least a subset of the services from theradio interface of the source radio base station to a radio interface ofthe target radio base station. The VNF manager also transfers the subsetof the services to the target radio base station through a route basedon information from a software-defined networking (SDN) controller of aSDN system that includes the source radio base station and the targetradio base station. The VNF manager causes at least one VNF to bedeployed on the target radio base station, the at least one VNF on thetarget radio base station being adapted to offer the subset of theservices to the roaming UE.

Non-transitory machine-readable storage media for delivering services toa roaming UE are disclosed. In one embodiment, a non-transitorymachine-readable medium having instructions stored therein, which whenexecuted by a processor, cause the processor to perform operations in avirtual network function (VNF) manager for delivering services to aroaming UE. The services are offered by a set of VNFs hosted on a sourceradio base station and are delivered to the roaming UE via a radiointerface of the source radio base station, where the roaming UE is toroam from a radio coverage area of the source radio base station into aradio coverage area of a target radio base station. The operationsinclude identifying a trigger condition for handing-over delivery of atleast a subset of the services from the radio interface of the sourceradio base station to a radio interface of the target radio basestation. The operations also include transferring the subset of theservices to the target radio base station through a route based oninformation from a software-defined networking (SDN) controller of a SDNsystem that includes the source radio base station and the target radiobase station. The operations further include causing at least one VNF tobe deployed on the target radio base station, the at least one VNF onthe target radio base station being adapted to offer the subset of theservices to the roaming UE.

Embodiments of the disclosed techniques provides efficient ways todeliver services using network function virtualization and SDN.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may best be understood by referring to the followingdescription and accompanying drawings that are used to illustrateembodiments of the invention. Like reference numbers and designations inthe various drawings indicate like elements. In the drawings:

FIG. 1 illustrates a high-level NFV framework.

FIG. 2 illustrates a network system for provisioning of services to aroaming UE according to one embodiment of the invention.

FIG. 3 illustrates a network system for provisioning of services to aroaming UE according to another embodiment of the invention.

FIG. 4 illustrates a network system for deploying a VNF on the targetradio base station according to one embodiment of the invention.

FIG. 5 illustrates a network system for deploying a VNF on the targetradio base station according to another embodiment of the invention.

FIG. 6 illustrates a flow diagram of a method embodiment in a VNFmanager for building a VNF according to one embodiment of the invention.

FIG. 7 illustrates a flow diagram of a method embodiment in a VNFmanager for provisioning of services to a roaming UE according to oneembodiment of the invention.

FIG. 8 illustrates a flow diagram of a method embodiment in a sourceradio base station for provisioning of services to a roaming UEaccording to one embodiment of the invention.

FIG. 9 illustrates a flow diagram of a method embodiment in a targetradio base station for provisioning of services to a roaming UEaccording to one embodiment of the invention.

FIG. 10 illustrates a schematic block diagram of a VNF manager apparatusembodiment for provisioning of services to a roaming UE according to oneembodiment of the invention.

FIG. 11 illustrates a schematic block diagram of a radio base stationapparatus embodiment for provisioning of services to a roaming UEaccording to one embodiment of the invention.

FIG. 12 illustrates two scenarios of radio handover and service transferscenario according to embodiments of the invention.

FIG. 13 illustrates a network system for provisioning of services to aroaming UE using a SDN controller according to one embodiment of theinvention.

FIG. 14 illustrates a network system for provisioning of services to aroaming UE using a SDN controller according to another embodiment of theinvention.

FIG. 15 illustrates a network system for deploying a VNF on a targetradio base station using a SDN controller according to one embodiment ofthe invention.

FIG. 16 illustrates a network system for deploying a VNF on a targetradio base station using a SDN controller according to anotherembodiment of the invention.

FIG. 17 is a flow diagram illustrating a method of a VNF managermanaging service delivery using a SDN controller according to oneembodiment of the invention.

FIG. 18A illustrates connectivity between network devices (NDs) withinan exemplary network, as well as three exemplary implementations of theNDs, according to some embodiments of the invention.

FIG. 18B illustrates an exemplary way to implement a special purposenetwork device according to some embodiments of the invention.

FIG. 18C illustrates various exemplary ways in which virtual networkelements (VNEs) may be coupled according to some embodiments of theinvention.

FIG. 18D illustrates a centralized approach for maintaining reachabilityand forwarding information (also called network control), according tosome embodiments of the invention.

FIG. 18E illustrates the simple case of where each of the NDs implementsa single NE, but a centralized control plane has abstracted multiple ofthe NEs in different NDs into (to represent) a single NE in one of thevirtual network(s), according to some embodiments of the invention.

FIG. 18F illustrates a case where multiple VNEs are implemented ondifferent NDs and are coupled to each other, and where a centralizedcontrol plane has abstracted these multiple VNEs such that they appearas a single VNE within one of the virtual networks, according to someembodiments of the invention.

FIG. 19 illustrates a general purpose control plane device withcentralized control plane (CCP) software according to some embodimentsof the invention.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth.However, it is understood that embodiments of the invention may bepracticed without these specific details. In other instances, well-knowncircuits, structures and techniques have not been shown in detail inorder not to obscure the understanding of this description. It will beappreciated, however, by one skilled in the art that the invention maybe practiced without such specific details. Those of ordinary skill inthe art, with the included descriptions, will be able to implementappropriate functionality without undue experimentation.

References in the specification to “one embodiment,” “an embodiment,”“an example embodiment,” etc., indicate that the embodiment describedmay include a particular feature, structure, or characteristic, butevery embodiment may not necessarily include the particular feature,structure, or characteristic. Moreover, such phrases are not necessarilyreferring to the same embodiment. Further, when a particular feature,structure, or characteristic is described in connection with anembodiment, it is submitted that it is within the knowledge of oneskilled in the art to effect such feature, structure, or characteristicin connection with other embodiments whether or not explicitlydescribed.

In the following description and claims, the terms “coupled” and“connected,” along with their derivatives, may be used. It should beunderstood that these terms are not intended as synonyms for each other.“Coupled” is used to indicate that two or more elements, which may ormay not be in direct physical or electrical contact with each other,co-operate or interact with each other. “Connected” is used to indicatethe establishment of communication between two or more elements that arecoupled with each other. A “set,” as used herein refers to any positivewhole number of items including one item.

An electronic device stores and transmits (internally and/or with otherelectronic devices over a network) code (which is composed of softwareinstructions and which is sometimes referred to as computer program codeor a computer program) and/or data using machine-readable media (alsocalled computer-readable media), such as machine-readable storage media(e.g., magnetic disks, optical disks, read only memory (ROM), flashmemory devices, phase change memory) and machine-readable transmissionmedia (also called a carrier) (e.g., electrical, optical, radio,acoustical or other form of propagated signals—such as carrier waves,infrared signals). Thus, an electronic device (e.g., a computer)includes hardware and software, such as a set of one or more processorscoupled to one or more machine-readable storage media to store code forexecution on the set of processors and/or to store data./For instance,an electronic device may include non-volatile memory containing the codesince the non-volatile memory can persist code/data even when theelectronic device is turned off (when power is removed), and while theelectronic device is turned on that part of the code that is to beexecuted by the processor(s) of that electronic device is typicallycopied from the slower non-volatile memory into volatile memory (e.g.,dynamic random-access memory (DRAM), static random-access memory (SRAM))of that electronic device. Typical electronic devices also include a setor one or more physical network interface(s) to establish networkconnections (to transmit and/or receive code and/or data usingpropagating signals) with other electronic devices.

A network device (ND) is an electronic device that communicativelyinterconnects other electronic devices on the network (e.g., othernetwork devices, end-user devices). Some network devices are “multipleservices network devices” that provide support for multiple networkingfunctions (e.g., routing, bridging, switching, Layer 2 aggregation,session border control, Quality of Service, and/or subscribermanagement), and/or provide support for multiple application services(e.g., data, voice, and video).

Terms

Within the context of the present application, the term “service” refersto communication services or application services. A communicationservice may be a packet transport service such as Internet browsing,file transfer, file download, streaming of audio/video or the like. Acommunication services may also be voice call, multimedia call, chat,messaging, conference, or the like. Application services may be anyservice offered by an application or a server such as processing taskson behalf of UE (such as MTC), gaming, sensor data upload, sensor dataanalysis, remote control (also as a result of the sensor data analysis),or surveillance tasks, or the like.

Within the context of the present application, the term “user equipment”(UE) refers to an electronic device for instance used by a person forhis or her personal communication. It can be a telephone type of device,for example a telephone or a SIP phone, cellular telephone, a mobilestation, cordless phone, or a personal digital assistant type of devicelike laptop, notebook, notepad equipped with a wireless data connection.The UE may also be associated with humans but also with non-humans likeanimals, plants, or even machines (MTC/M2M). A UE may be equipped with aSIM (Subscriber Identity Module) comprising unique identities such asIMSI (International Mobile Subscriber Identity) and/or TMSI (TemporaryMobile Subscriber Identity) associated with the person using the UE suchas a subscriber using the UE. The presence of a SIM within a UEcustomizes the UE uniquely with a subscription of the subscriber. Suchsubscriber may also use multiple devices/UEs at the same time.

Within the context of the present application, the term “subscriber” mayrefer to a human being having a service agreement with a serviceprovider such as an operator. The subscriber may also be a legal entitysuch as a company operating a pool of MTC devices, and these devicesoperate independent from any human subscriber. In this case the MTCdevice is the direct receiver of the service while the servicesubscription is centrally with the company (indirect receiver of suchservice) operating the pool of MTC devices.

Within the context of the present application, the term “communicationnetwork” or short “network” may particularly denote a collection ofnodes or entities, related transport links, and associated managementneeded for running a service, for example a telephony service or apacket transport service. Depending on the service, different node typesor entities may be utilized to realize the service. A network operatorowns the communication network and offers the implemented services toits subscribers. Typical examples of a communication network are radioaccess network (such as 2G (2nd Generation), GSM (Global System forMobile communications), 3G (3rd Generation), WCDMA (Wideband CodeDivision Multiple Access), CDMA (Code Division Multiple Access), LTE(Long Term Evolution), WLAN (Wireless Local Area Network), Wi-Fi(Wireless Fidelity)), mobile backhaul network, or core network such asIMS (IP Multimedia System), CS (Circuit Switched) Core, PS (PacketSwitched) Core and 5G. The communication network may also include onesusing other wireless communication protocols (such as Bluetooth, ZigBee(ZigBee 2004, 2006, PRO), Z-wave (Z-Wave Alliance), Wi-Fi (IEEE 802.11),wireless personal area network technology (e.g., IEEE 801.15.4), DigitalEuropean Cordless Telecommunications (DECT), and WiMax) and ones usingwireline media such as optical fibers, copper lines, or power lines.

Within the context of the present application, the term “roaming” refersto a movement of a UE within a coverage area of a communication network.In order to receive services, the UE is registered in a control nodebeing responsible for the geographical area where the UE is currentlylocated and is attached via a radio interface to a radio base station.While moving, the UE may leave the radio coverage area of the currentradio cell offered by a current radio base station, the so called sourceradio base station, and move into a radio cell offered by a furtherradio base station, the so called target radio base station. Thisroaming may or may not have implications on the control node where theUE is registered. So if both, source radio base station and target radiobase station are under control of the same control node, theregistration in the control node is maintained. If source radio basestation and target radio base station are under control of differentcontrol nodes, also the registration is moved. For a circuit switchedservices the control nodes are typically MSC (Mobile Services Center)nodes, for packet switched communication services control nodes aretypically MME (Mobility Management Entity) nodes for the packet deliveryand application servers as provided for example by the IP MultimediaSubsystem (IMS).

Within the context of the present application, the term “control node”refers to a node of the communication network primarily performingcontrol procedures for sessions or calls and services of a subscriber ofthe communication network. The term typically refers to those entitiesof the communication network handling control plane, subscriber data,services, or signaling traffic associated with subscriber traffic in thecommunication network. In a core network a control node may be a MSC,MME (Mobility Management Entity), SGSN (Serving Gateway Support Node),P-CSCF (Proxy Call State Control Function), S-CSCF (Serving-CSCF), orTAS (Telephony Application Server) node.

Within the context of the present application, the term “packet controlnode” refers to a control node of the packet core network. Examples ofpacket control node are MME or SGSN.

Within the context of the present application, the term “subscriberdatabase” refers to a database run by the network operator to store theinformation related to the subscribers of a network run by the operator.A subscriber database can be for example a Home Location Register (HLR),a Visited Location Register (VLR), a Home Subscriber Server (HSS), or acombination of HLR and HSS. A subscriber database may also be internallystructured into a front end part handling the signaling with the othernetwork nodes of the communication network and a generic database forstorage of the data according to data layered architecture principles.

Within the context of the present application, the term radio basestation refers to a node of a radio access network that is used asinterface between land-based transport links and radio based transportlinks, wherein the radio based transport link interfaces directly a UE.For example, in a GSM/2G access network a radio base station refers toas a BTS, in a WCDMA/3G access network a radio base station refers to asa NodeB, and in a LTE access network a radio base station refers to asan eNodeB. In a WLAN/Wi-Fi architecture a radio base station refers toas an Access Point (AP).

Within the context of the present application, the term “virtual networkfunction (VNF)” may particularly denote a concept taking on theresponsibility of handling one or more specific network functions. Suchconcept may be realized by running that VNF on one or more virtualmachines (VMs) on top of a hardware networking infrastructure—e.g.routers, switches, servers, hosting infrastructure, etc. In alternative,the term VNF may also stand for a software container concept that allowsrunning software processes/function in isolation from each other on acommon hosting infrastructure. Containers, unlike a virtual machine, donot require or include a separate operating system. Instead, it relieson kernel's functionality and uses resource isolation (CPU, memory,block input/output (I/O), network, etc.) and separate namespaces toisolate the application's view of the operating system. Due to the factthat containers do not include an operating system, the size of acontainer is typically smaller than of an entire virtual machine. Alongthese lines, the term VNF may also stand for a micro-service concept.The micro-service architectural concept is an approach to develop afunction as a suite of smaller functions, each running in its ownprocess and communicating with lightweight mechanisms (e.g. Hypertexttransfer protocol (HTTP) resource application programming interface(API)). These functions are independently deployable by fully automateddeployment machinery (e.g. a manager herein called VNF manager).

Provisioning Services for a Roaming UE

Individual virtual network functions may be connected, combined, orchained together as building blocks to offer a full-scale service.Instead of using multiple individual VNFs and chaining the VNFs togetherfor a full-scale service, it is also possible to merge/combine severalof the sub-functions into single VNF. Such VNF would comprise allelements and sub-functions for the provisioning of a service, or evenmultiple/all services provided to a UE. Typically, such VNF would stillserve multiple UEs and multiple subscribers.

In an alternative deployment the VNF could comprise all functions forthe provisioning of multiple/all services provided to the UE, but theVNF would be dedicated for that single UE or a single subscriber. Thisconcept may be taken a step further, and a VNF could be dedicated for asingle service for a single UE. In such scenario, considering that themultiple services are provided to the single UE, several VNFs areinvolved in provisioning of the services to that UE.

Several permutations are possible for the scenario involving severalVNFs per UE: (1) one VNF per UE and service; (2) one VNF persubscription, so private services provided by one VNF and enterpriseservices provided by another VNF, in addition there may still be one VNFper service; (3) one VNF per service type or based on specificrequirements of the service (e.g. premium class services versusbest-effort services. Thus there are one or several VNFs per UE forprovisioning the services to the UE.

In the further description the term “source” radio base station and“target” radio base station are used to distinguish the different rolesa radio base station can take. It shall be clear to a technicallyskilled person to understand that a “target” radio base station can actas a “source” radio base station when the roaming movement of the UEcontinues. So the UE may also revert its moving direction and by thatcause the former “target” radio base station to become a “source” radiobase station for the movement back, and the former “source” radio basestation becoming a “target” radio base station.

Referring now to FIG. 2, which illustrates a network system forprovisioning of services to a roaming UE, according to one embodiment ofthe invention. A UE 200 is roaming around and moves from the upperposition to the lower position. In the upper position the UE 200 isconnected to the source radio base station 210 via a radio interface. Inthis embodiment the services are offered by VNF-1 240 and VNF-2 245hosted on the source radio base station 210, and the services aredelivered to the roaming UE via a radio interface of the source radiobase station 210. It is to be noted that a service is described hereinas either being delivered to or provisioned at a UE, and the deliveryand provisioning of a service are used interchangeably herein and meansthe VNF manager, through one or more VNFs, causes the service beingoffered at the UE.

The roaming UE is then roaming from a radio coverage area of the sourceradio base station 210 into a radio coverage area of a target radio basestation 220. In the lower position the UE 200 is connected to the targetradio base station 220 via a radio interface, where the services areoffered by VNF-1 250 and VNF-2 255 hosted on the target radio basestation 220, and the services are delivered to the roaming UE via aradio interface of the target radio base station 220.

This embodiment shows the case where two VNFs 240, 245 (and VNFs 250,255 after handing-over the service provisioning) are used to provisionservices to the roaming UE 200. For example, VNF-1 240 may offer a firstset of services, and VNF-2 245 may offer a second set of services. Asdescribed above, there may be one of more VNFs per roaming UE.

The movement of the UE 200 causes that at some point of time during themovement, there is a need for handing-over the delivery of the servicesfrom the radio interface of the source radio base station 210 to theradio interface of the target radio base station 220. This is done bydetermining a trigger condition for handing-over the delivery of theservices from the radio interface of the source radio base station 210to the radio interface of the target radio base station 220.

The trigger condition for handing-over may be met if the roaming UE 200leaves the radio coverage area of the source radio base station 210,where the radio signal strength of the radio interface of the sourceradio base station 210 is fading and at the same time the radio signalstrength of the radio interface of the target radio base station 220 isfound to be on an acceptable level. In this case this trigger conditionmay be a radio signal strength threshold, and the trigger conditionwould be met if the threshold is reached or exceeded.

If this trigger condition is met, a VNF manager 230 is caused to deployVNF-1 250 and VNF-2 255 on the target radio base station 220. Thiscausing may be done by the source radio base station 210 by sending anappropriate signaling message to the VNF manager 230 informing that thecondition for handing-over the provisioning of the services has beenmet.

As an alternative, the source radio base station 210 and target radiobase station 220 may continuously send radio signal strengthmeasurements to the VNF manager 230 and the VNF manager 230 determineswhen to trigger handing-over the provisioning of the services. The VNFmanager 230 may apply a similar radio signal strength threshold astrigger condition.

The VNF-1 250 and VNF-2 255 on the target radio base station 220 areadapted for offering the provisioned services to the roaming UE 200.After deploying VNF-1 250 and VNF-2 255 on the target radio base station220, the services are continued to be provisioned to the roaming UE 200.This is done by delivering the services via the radio interface of thetarget radio base station 220 to the roaming UE 200.

After the handing-over is completed, so that VNF-1 250 and VNF-2 255 aredeployed on the target radio base station 220, the corresponding VNF-1240 and VNF-2 245 may be deleted on/removed from the source radio basestation 210. This may be initiated by the VNF manager 230 after thehanding-over is completed, for example after reception of a confirmationfrom the target radio base station 220 that the services are continuedto be provisioned to the roaming UE 200. By alternative, this may betriggered by the source radio base station 210 itself, for example afterproviding a clone copy of VNF-1 240 and VNF-2 245 to the VNF manager 230or the destination radio base station 220.

The VNF manager 230 is caused to deploy VNF-1 250 and VNF-2 255 on thetarget radio base station 220. The VNF manager 230 may do this bydeploying a clone of VNF-1 240 and VNF-2 245 hosted on the source radiobase station 210 to the target radio base station 220. The VNF manager230 may request the source radio base station 210 to provide a copy ofthe VNF-1 240 and VNF-2 245 and forward these to the target radio basestation 220 to be deployed as VNF-1 250 and VNF-2 255.

In alternative, instead of retrieving a copy of the VNF-1 240 and VNF-2245 from the source radio base station 210, the VNF manager 230 maybuild VNF-1 250 and VNF-2 255 based on construction information on theprovisioned services. That construction information may be retrievedfrom a database 260 (shown in FIG. 5) and described in further detailbelow.

The VNF manager 230 may build VNF-1 250 and VNF-2 255 by retrievingfunction components from a library 270 comprising function components ofa communication network (shown in FIG. 5) and described in furtherdetail below.

The UE 200 may continue to roam and the above method is repeated severaltimes. Thus the VNFs serving the roaming UE 200 are moved along with theroaming movement of the UE 200 and the radio coverage.

It shall be noted that this embodiment shows the scenario where two VNFsare dedicated to the roaming UE 200, and that both of them arehanded-over from the source radio base station 210 to the target radiobase station 220. In this case the distribution of the offering of theservices over the VNFs 240, 245 is based on for example the servicesprovisioned to the roaming UE 200. By alternative, the services may bedistributed base on a subscription profile of a subscriber using theroaming UE 200. It is to be noted that in other embodiments there may bemore than two VNFs, or even just a single VNF.

The UE 200 may continue to roam and the above method is repeated.

Referring now to FIG. 3, which illustrates a network system forprovisioning of services to a roaming UE, according to anotherembodiment of the invention. FIG. 3 shows a similar scenario as in FIG.2. The UE 200 is roaming around and moves from the upper position to thelower position. In the upper position the UE 200 is connected to thesource radio base station 210 via a radio interface. The services areoffered by VNF-1 240 and VNF-2 245 hosted on the source radio basestation 210 and the services are delivered to the roaming UE via a radiointerface of the source radio base station 210.

The roaming UE is then roaming from a radio coverage area of the sourceradio base station 210 into a radio coverage area of a target radio basestation 220. In the lower position the UE 200 is connected to the targetradio base station 220 via a radio interface.

However, in this embodiment, in the lower position the services areoffered by VNF-1 250 hosted on the target radio base station 220 and inaddition offered by VNF-2 245 still located on the source radio basestation 210. The VNF-2 245 is connected via a network interface 280 tothe target radio base station 220. The services are then delivered tothe roaming UE via a radio interface of the target radio base station220. The network interface 280 may be a channel utilizing one or morenetwork transmission links such as a direct land-based connection ormicrowave radio based transmission links between the two radio basestations 210 and 220. Radio base stations are typically hooked up to abackhaul network connecting them to the core network. Thus such networkinterface 280 between two radio base stations may also be realized byrouting/switching via backhaul network connections or even byrouting/switching via a core network node. The network interface 280 maybe based on routed packets connections or pre-established packet tunnelsusing well-known layer 2 or layer 3 tunnel mechanisms.

In this embodiment, the VNF manager 230 is handing-over a subset of theservices from the source radio base station 210 to the target radio basestation 220. The remaining (not handed-over) services are continued tobe offered by the VNF-2 245 in the source radio base station 210 and aredelivered to the roaming UE 200 via the radio interface of the targetradio base station 220.

The VNF manager 230 decides the service subset to be handed-over basedon the service provisioned to the roaming UE 200, or the subscriptionprofile of the subscriber using the roaming UE 200.

In this scenario the VNF manager 230 deploys just VNF-1 250 on thetarget radio base station 220. VNF-1 250 may be a clone copy of VNF-1240 from the source radio base station 210, or may be newly built by theVNF manager 230 as described in FIG. 5 below.

It shall be noted that this embodiment shows the scenario where two VNFsare dedicated to the roaming UE 200, and that one of them is handed-overfrom the source radio base station 210 to the target radio base station220. In this case the distribution of the offering of the services overthe VNFs 240, 245 may also be based on the services provisioned to theroaming UE 200 or on a subscription profile of a subscriber using theroaming UE 200.

In other embodiments there may be more than two VNFs, for example fiveVNFs, and two of them are handed-over to the target radio base station220, while three of them remain on the source radio base station 210.Various other combinations of number of handed-over VNFs and VNFsremaining can be thought of, if determined useful for the provisionedservices or subscription profile by the VNF manager 230.

For example, services that have very demanding latency requirements maybe handed-over to the target radio base station 220, while others havingless stringent latency requirements may be left at the source radio basestation 210 and are delivered via network interface 280.

The UE 200 may continue to roam and the above method is repeated. So theVNFs remaining on the source radio base station 210 stay even further onthat source radio base station 210, while the handed-over VNFs arehanded-over again to a next target radio base station 220, and so on.

Optionally, at each trigger condition for handing-over VNFs, the VNFmanager 230 may take another decision whether to hand-over the VNF inthe source radio base station 210. So if, after the UE having moved fora longer distance, or if the service delivery via the network interface280 from the source radio base station 210 to the next target radio basestation 220 experiences an increased latency (for example if transportedover slow speed connections or delay intensive microwave links), the VNFmanager 230 may decide to commonly hand-over VNFs from the source radiobase station 210 and from a previous target radio base station 220 to anew target radio base station 220. In this scenario all VNFs offeringservices to the UE 200 would be gathered at the new target radio basestation 220 and the system is again in the starting situation asdepicted in FIGS. 2 and 3.

Referring now to FIG. 4, this figure illustrates a network system fordeploying a VNF on the target radio base station, according to oneembodiment of the invention. In this embodiment the cloning of a VNFfrom a source radio base station 210 to a target radio base station 220is illustrated in more details.

The cloning may be triggered by an indication received by the VNFmanager 230 from the source radio base station 210 that a handing-overof the delivery of the services from the radio interface of the sourceradio base station 210 to the radio interface of a target radio basestation 220 is needed. This trigger may for example be based on the UE200 leaving the radio coverage area of the source radio base station210. By alternative, this first step may also be triggered by the targetradio base station 220, for example when a UE 200 enters the radiocoverage area of the target radio base station 220.

After having determined which of the VNFs to hand-over, the VNF manager230 may in a second step request a clone copy of the one or moredetermined VNFs from the source radio base station 210. The source radiobase station 210, receiving such request, may produce a clone copy bytaking a current snapshot of the requested, running VNF, in order tocapture the current dynamic state of the VNF. Then the source radio basestation 210 returns that clone copy to the VNF manager 230. The VNFmanager 230 may request more than one clone copy; in this case thesource radio base station 210 may provide this plurality of clone copiesin a single response, or in several responses or sub-responses(segmented response). By alternative, the VNF manager 230 may requestone VNF at a time, however, this would prolong the handing-over time.

The VNF manager 230 may also request clone copies of one or more VNFsfrom several source radio base stations such as source radio basestation 210, in case of continued roaming of the UE and previous partialhanding-over of VNFs as described above.

In a third step the VNF manager 230 deploys the one or more VNFs on thetarget radio base station 220. The one or more VNFs on the target radiobase station 220 are adapted for offering at least a subset of theprovisioned services to the roaming UE 200.

Referring now to FIG. 5, which illustrates a network system fordeploying a VNF on the target radio base station, according to anotherembodiment of the invention. In this embodiment the building of a VNF bythe VNF manager 230 is illustrated in more details.

In a first step VNF building may be triggered by an indication receivedby the VNF manager 230 from the source radio base station 210 that ahanding-over of the delivery of the services from the radio interface ofthe source radio base station 210 to the radio interface of a targetradio base station 220 is needed. This trigger may for example be basedon the UE 200 leaving the radio coverage area of the source radio basestation 210. By alternative, this first step may also be triggered bythe target radio base station 220, for example when a UE 200 enters theradio coverage area of the target radio base station 220.

In this embodiment the VNFs to be deployed on the target radio basestation 220 is not a clone copy of a VNF in the source radio basestation 210 but a newly built VNF. The VNF manager 230 may decide to usethe clone copy method or the method to build the VNFs anew. The VNFmanager 230 may use different decision criteria such as number ofprovisioned services, complexity of the provisioned services, size ofthe resulting VNF and the like. The VNF manager 230 may also check thecapabilities/type of NFVI provided by the target radio base station 220.Thus the NFVI provided by the target radio base station 220 may requirea different building of the VNF than used on the source radio basestation 210, so that a VNF clone copy of source radio base station 210would not be compatible with the target radio base station 220 in thatcase.

In the second step, the VNF manager 230 has to determine the componentsthat the VNF shall comprise, that are all components required foroffering the provisioned services to the UE 200. In order to do this,the VNF manager 230 may query a database. This database may be anOperation Support System (OSS), a Business Support System (BSS), or aNetwork Management System (NMS). Such database may be located stillwithin the communication network.

It is to be noted that the VNF manager 230 has to determine the servicesthat the subscriber has subscribed to and is currently using. As aresult, the VNF manager 230 receives construction information on how tobuild the needed (one or more) VNF(s). Based on this constructioninformation, the VNF manager 230 may in a third step retrieve therequired software components from a library comprising communicationnetwork components. For example, the VNF construction information maydemand that a Packet Gateway (PGW), a Mobility Management Entity (MME),a Policy and Charging Rules Function (PCRF), application-1,application-2, and application-3 would be required. The VNF manager 230then retrieves these software components from the library.

In a fourth step the VNF manager 230 builds the VNF based on theconstruction information, the software components from the library, andparticular building method required for the NFVI provided by the targetradio base station 220. The readily built VNF is then in a fifth stepdeployed on the target radio base station 220.

These steps may be repeated if more than one VNF needs to be deployed,or these steps may be performed in parallel in order to build and deploymultiple VNFs. The one or more VNFs on the target radio base station 220are adapted for offering at least a subset of the provisioned servicesto the roaming UE 200.

Flow Diagrams for a VNF Manager Managing Service Provisioning

Referring now to FIG. 6, which illustrates a flow diagram of a methodembodiment in a VNF manager 230 for building a VNF according to oneembodiment of the invention. This flow diagram illustrates the steps forbuilding one or more VNF corresponding to FIG. 5. The flow starts instep 600 where services are provisioned to the roaming UE 200 via thesource radio base station 210.

In step 610 the VNF manager 230 receives an indication from the sourceradio base station 210 for handing-over the delivery of the services.The VNF manager 230 decides whether to retrieve a clone copy of the VNFsfrom the source radio base station 210, or whether to build new VNFs. Inthis embodiment, the VNF manager 230 decides to build new VNFs.

In step 620 the VNF manager 230 retrieves VNF construction informationfrom a database. Based on this VNF construction information, the VNFmanager 230 retrieves in step 630 VNF components from a library ofcommunication network components.

In step 640 the VNF manager 230 builds the VNF based on the constructioninformation using the components retrieved from the library. The VNFmanager 230 also initializes the built VNF. In step 650 the VNF manager230 deploys the built VNF on the target radio base station 220.

These steps may be repeated if more than one VNF needs to be deployed,or these steps may be performed in parallel for more than one VNF to bedeployed.

The one or more VNFs on the target radio base station 220 are adaptedfor offering at least a subset of the provisioned services to theroaming UE 200.

Referring now to FIG. 7, which illustrates a flow diagram of a methodembodiment in a VNF manager 230 for provisioning of services to aroaming UE according to one embodiment of the invention. This flowcorresponds to the network scenario as shown in FIG. 3.

The flow starts in step 700 where the services are provisioned to theroaming UE 200 via the source radio base station 210.

In step 710 the VNF manager 230 receives an indication from the sourceradio base station 210 for handing-over the delivery of the services. Inthis particular embodiment a subset of the services is to be handed-overfrom the source radio base station 210 to the target radio base station220. The remaining services are continued to be offered by the VNFs inthe source radio base station 210 and are delivered to the roaming UE200 via the radio interface of the target radio base station 220.

In step 720 the VNF manager 230 determines the VNFs that need to behanded-over to the target radio base station 220. The VNF manager 230may perform this determination based on the services that the VNF isoffering to the UE 200. The services that have very demanding latencyrequirements may be handed-over to the target radio base station 220,while others having less stringent latency requirements may be left atthe source radio base station 210 and are delivered via networkinterface 280.

After having decided which of the VNFs in the source radio base station210 need to be handed-over to the target radio base station 220, in step730 the VNF manager 230 may retrieve a clone copy from the source radiobase station 210 of the VNFs that have been determined to behanded-over. Instead of retrieving a clone copy, the VNF manager 230 mayalso build a new VNF as described in FIGS. 5 and 6.

In step 740 the VNF manager 230 deploys the VNF on the target radio basestation 220. Finally in step 750 the VNF manager 230 instructs thesource radio base station 210 to interface the target radio base station220 for delivery of the remaining services to the UE 200 via the networkinterface 280 to the target radio base station.

The one or more VNFs on the target radio base station 220 and theremaining one or more VNFs on the source radio base station 210,together are adapted for offering the provisioned services to theroaming UE 200.

Referring now to FIG. 8, which illustrates a flow diagram of a methodembodiment in a source radio base station 210 for provisioning ofservices to a roaming UE, according to one embodiment of the invention.

The flow starts in step 800 when the source radio base station 210determines a trigger condition for handing-over the delivery of theservices to a target radio base station 220.

In step 810 the source radio base station 210 sends an indication to theVNF manager 230 to initiate handing-over of the one or more VNFs. Thisembodiment assumed the situation that the VNF manager 230 builds newVNFs. In this case the source radio base station 210 will not receiveany request for providing a clone copy of the VNFs on the source radiobase station 210.

In step 820 the source radio base station 210 receive an instructionfrom the VNF manager 230 to interface the target radio base station 220for delivery of remaining services still offered by VNFs on the sourceradio base station 210. That interface may be the interface 280. It isto be noted that step 820 is optional and is used when the VNF manager230 determines to hand-over a subset of the VNFs from the source radiobase station 210 to the target radio base station 220.

Referring now to FIG. 9, which illustrates a flow diagram of a methodembodiment in a target radio base station 220 for provisioning ofservices to a roaming UE according to one embodiment of the invention.

The flow starts in step 900 when the target radio base station 220receives at least one VNF for deployment on the target base station 220from the VNF manager 230. The target radio base station 220 then deploysthe received VNFs, initializes and starts them.

In step 910 the deployed VNF continues to offer the provisioned servicesand delivery of the services is via the radio interface of the targetradio base station 220 to the UE 200. In addition, the target basestation 220 may in step 920 receive services via the network interface280. These received services are offered by remaining VNFs in the sourceradio base station 210 and are delivery to the roaming UE 200 via theradio interface of the target radio base station 220. This last step isoptional and is used when the VNF manager 230 determines to hand-over asubset of the VNFs from the source radio base station 210 to the targetradio base station 220

Apparatus Block Diagrams

Referring now to FIG. 10, which illustrates a schematic block diagram ofa VNF manager apparatus embodiment for provisioning of services to aroaming UE according to one embodiment of the invention. The VNF managerapparatus may be implemented in an electronic device or be theelectronic device itself and it may be adapted to perform method stepsaccording to the methods illustrated in block and flow diagramsdiscussed herein. The VNF manager 230 may comprise a number offunctional units, which are described in further detail below and whichare adapted to perform respective method steps.

A processing unit 1000 of the VNF manager 230 may be adapted to executesteps for provisioning of services to a roaming UE. The processing unit1000 handles reception of an indication from a source radio base station210 for handing-over the delivery of the services from the radiointerface of the source radio base station 210 to the radio interface ofa target radio base station 220. The processing unit 1000 also handlesdeployment of at least one VNF on the target radio base station 220.

In a practical implementation the processing unit 1000 may be oneprocessor taking care of all the above functions, or may also bedistributed over more than one processor, wherein the functions aredistributed over the available processors. The VNF manager 230 may be aVNF itself, e.g. instantiated by a master VNF manager running on thesame or a further NFVI.

The VNF manager 230 may further comprise a sending unit 1010 and areceiving unit 1020 via which the VNF manager 230 can communicate withother physical entities or external VNFs such as the source radio basestation 210, the target radio base station 220, or VNFs deployedtherein. The sending unit 1010 may send out signaling messages composedby the processing unit 1000. The receiving unit 1020 may receivesignaling messages from those external entities above and forward thereceived signaling messages to the processing unit 1000 for decodingand/or dispatching. The VNF manager 230 may further comprise a networkinterface to a database 260 for retrieval of construction informationfor building a VNF, or to a library 270 comprising function componentsof a communication network for building a VNF. The receiving unit 1020may retrieve a clone copy of a VNF from a source radio base station 210,and the sending unit 1010 may send the clone copy of the VNF to thetarget radio base station 220 for deployment. The sending unit 1010 mayalso send a VNF to the target radio base station 220, which has beenbuilt by the VNF building unit 1040.

The VNF manager 230 may also comprise a storing unit 1030 for storinginformation related to provisioning of services to a roaming UE. Thestoring unit 1030 may keep a cache of frequently used VNFs, or a VNFskeleton/framework which can be tailored to specific task/serviceprovisioning by adding configuration or by proper initialization. Thestoring unit 1030 may be a pure software functional module such as a SQLdatabase software module. The storing unit 1030 may also have access toand/or use a centralized storage (e.g. a Network Attached Storage, NAS)comprising various types of memory such as volatile memory, non-volatilememory, hard disk drives, solid state drives, a network interface to adatabase or a data center, secure digital cards, or hardware such assmart cards, non-reversible chips, security chips, security modules, ortrusted platform module devices. The storing unit 1030 may be used bythe processing unit 1000 to store information, for example program codeor data related to VNF manager 230 tasks. The storing unit 1030 may alsohost a database of construction information 260 and/or a library ofcommunication network components 270.

The VNF manager 230 may further comprise a VNF building unit 1040. ThisVNF building unit 1040 may retrieve VNF construction information forbuilding a VNF, retrieve either externally, or internally if hosted bythe storing unit 1030. Based on this VNF construction information theVNF building unit 1040 may retrieve the required software componentsfrom a library 270 comprising function components of a communicationnetwork for building a VNF. Also this library 270 may be hosted by thestoring unit 1030. The VNF building unit 1040 may then build a VNF andinitialize that VNF for deployment. The VNF is then deployed to thetarget radio base station 220 via the sending unit 1010.

The VNF manager 230 may also comprise a determination unit 1050. Thisdetermination unit 1050 is used to determining a trigger condition forhanding-over the delivery of the services from the radio interface ofthe source radio base station 210 to a radio interface of a target radiobase station 220. The trigger condition for handing-over may be met ifthe roaming UE 200 leaves the radio coverage area of the source radiobase station 210, so if the radio signal strength of the radio interfaceof the source radio base station 210 is fading and at the same time theradio signal strength of the radio interface of the target radio basestation 220 is found to be on an acceptable level.

Referring now to FIG. 11, which illustrates a schematic block diagram ofa radio base station apparatus embodiment for provisioning of servicesto a roaming UE, according to one embodiment of the invention. The radiobase station may be adapted to perform method steps according to themethods discussed in relation to FIG. 8 or 9. The illustrated radio basestation may be adapted to act as a source radio base station 210 and asa target radio base station 220, at the same time for different UEs, andat different times for the same UE.

The radio base station 210, 220 may comprise a number of functionalunits, which are described in further detail below and which are adaptedto perform respective method steps.

A processing unit 1100 of the radio base station 210, 220 may be adaptedto execute steps for provisioning of services to a roaming UE accordingto one embodiment of the invention. The processing unit 1100 causes, ifa trigger condition is met, a VNF manager 230 to deploy at least one VNF250, 255 on a target radio base station 220. The processing unit 1100may also deploy a received VNF on its NFVI 1160. In a practicalimplementation the processing unit 1100 may be one processor taking careof all the above functions, or may also be distributed over more thanone processor, wherein the functions are distributed over the availableprocessors.

The radio base station 210, 220 may further comprise a sending unit 1110and a receiving unit 1120 via which the radio base station 210, 220 cancommunicate with other physical entities or external VNFs such as theVNF manager 230 or a further radio base station 210, 220. The sendingunit 1110 may send out signaling messages composed by the processingunit 1100. The receiving unit 1120 may receive signaling messages fromthose external entities above and forward the received signalingmessages to the processing unit 1100 for decoding and/or dispatching.When working as a source radio base station 210, the radio base stationmay further comprise a network interface 280 to a target radio basestation 220 for delivery of services offered by local VNFs for deliveryvia a radio interface of the further radio base station to the UE 200.When working as a target radio base station 220, the radio base stationmay use that same network interface 280 for receiving services from asource radio base station 210 for delivery to the UE 200 via the radiointerface unit 1140. That network interface may be a separate unit orcombined with that sending unit 1110 and a receiving unit 1120. Thereceiving unit 1120 may receive for deployment on the NFVI 1160 one ormore VNF. Such VNF may be a clone copy of a VNF from a source radio basestation 210, or a VNF built by a VNF manager 230.

The radio base station 210, 220 may also comprise a storing unit 1130for storing information related to provisioning of services to a roamingUE. The storing unit 1130 may be a pure software functional module suchas a SQL database software module. The storing unit 1130 may also haveaccess to and/or use a centralized storage (e.g. a Network AttachedStorage, NAS) comprising various types of memory such as volatilememory, non-volatile memory, hard disk drives, solid state drives, anetwork interface to a database or a data center, secure digital cards,or hardware such as smart cards, non-reversible chips, security chips,security modules, or trusted platform module devices. The storing unit1130 may be used by the processing unit 1100 to store information, forexample program code or data related to radio base station 210, 220tasks.

The radio base station 210, 220 may further comprise a radio interfaceunit 1140 comprising a sending a receiving part. The radio interfaceunit 1140 is utilized for radio communication with the UE 200. So theradio interface unit 1140 may send messages and data related to theprovisioned services to the UE 200 and receive messages and data relatedto the provisioned services from the UE 200. The services may be offeredby VNFs locally in the radio base station 210, 220, or are received viaa network interface 280 from a further radio base station 210, 220,hosting VNFs that have not been handed-over.

The radio base station 210, 220 may also comprise a determination unit1150. The determination unit 1150 determines a trigger condition forhanding-over the delivery of the services from the radio interface ofthe source radio base station 210 to a radio interface of a target radiobase station 220. The trigger condition for handing-over may be met ifthe roaming UE 200 leaves the radio coverage area of the source radiobase station 210, so if the radio signal strength of the UE 200 isfading. The radio signal strength may be determined with the help of theradio interface unit 1140 for example by taking own measurements, or bymeasurements reported from a UE 200.

The radio base station 210, 220 may further comprise a NFVI 1160. TheNFVI 1160 is adapted to host VNFs such as VNFs for offering of servicesto a roaming UE 200. The NFVI 1160 comprises hardware resources, whichare abstracted by a Virtualization Layer. VNFs received from a VNFmanager 230 may be deployed on the NFVI 1160.

According to another embodiment, a computer program is provided. Thecomputer program may be executed by the processing units 1000 and/or1100 of the above mentioned entities 210, 220 and/or 230 respectivelysuch that a method for provisioning of services to a roaming UE asdescribed above with reference to FIGS. 6 to 9 may be carried out or becontrolled. In particular, the entities 210, 220 and/or 230 respectivelymay be caused to operate in accordance with the above described methodby executing the computer program.

The computer program may be embodied as computer code, for example of acomputer program product. The computer program product may be stored ona computer readable medium, for example a disk or the storing unit 1030and/or 1130 of the entities 210, 220 and/or 230 respectively, or may beconfigured as downloadable information.

One or more embodiments as described above may enable at least one ofthe following technical effects: (1) Continuously provisioning ofservices to a UE while roaming; (2) reduce service latency and networktransmission bandwidth due to processing close to the UE location; (3)selectively exclude VNFs from being handed-over, deliver the relatedservices to the UE via the radio interface of the target base station;(4) flexibility of VNF allocation: per subscription, per UE, or perservice; and (5) improving network flexibility, so to make it possibleto allocate less-important VNFs to hosts across the network that havespare resources.

Service Handover Scenarios

Service handover discussed herein includes connection termination andreestablishment, and have two basic scenarios: make-before-break andbreak-before-make

In a make-before-break scenario, a new connection is established beforean existing one is taken away, so that for a short period of time theexisting and new connections co-exist. This allows for a smooth handoveras there is at least one connection during the handover, thus there isno interruption. If the establishment of the new connection fails, afallback to the existing one is easy as the existing connection has notbeen removed yet. In the roaming UE case though, if the handover fails,the existing connection would be removed after a period of time when theradio strength of the source radio base station fades due to themovement of the UE. Because the co-existence of the new and existingconnections, the resource usage in make-before-break is higher than thebreak-before-make

In a break-before-make scenario, the existing connection is broken firstand then the new connection is established. This scenario is referred toas hard handover sometimes as the connection is broken for a shortperiod of time. If the establishment of the new connection fails, theconnectivity is lost immediately. The resource usage inbreak-before-make is lower, but in order to keep the interruption small,the “make” process needs to be quick. In the roaming UE case, thebreak-before-make scenario is applicable when it is impractical to haveboth radio links at the source and target radio base stations active atthe same time (as it would require dual transceivers or at least a veryfast re-tuning between sending and receiving slots and differentfrequencies or even different radio technologies), or when the loss ofdata due to interruption can be compensated by fast re-transmission orrepair mechanism of an upper transport layer.

The handing-over of service provisioning from a source radio basestation to a target radio base station includes two aspects: 1) changeof radio connection between the UE and the source radio base stationtoward between the UE and the target radio base station; and 2) move ofone or services offered by the VNFs from the source radio base stationto the target radio base station. The make-before-break andbreak-before-make scenarios apply to both aspects, i.e., both the radiohandover and the service transfer can use either make-before-break orbreak-before-make method. Yet, for handing-over of service provisioning,only two out of the four possible permutations are sensible with thegoal of minimizing service interruption time. FIG. 12 illustrates twoscenarios of radio handover and service transfer scenario according toembodiments of the invention.

In the first scenario, the radio connection between the UE and thesource radio base station remains intact while the radio connectionbetween the UE and the target radio base station is established. Afterthe radio connection is handed over, the service provisioning functionof a set of services is then transferred (e.g., through a VNF transferor VNF rebuild) to the target radio base station. In this scenario, theinterruption of service provisioning is minimum, and the VNF on thesource radio base station continues to offer the service, with theparallel connections of the UE to the source and target radio basestation.

In the second scenario, the radio connection between the UE and thesource radio base station is broken first before the radio connectionbetween the UE and the destination radio base station is established.Yet, the service provisioning function of a set of services has beentransferred to the target radio base station. The break of radioconnection may cause interruption of service provisioning thus thesecond scenario is applicable to service provisioning that someinterruption is acceptable.

The VNF manager coordinating the handover determines which scenario toapply in one embodiment. The determination may be based on a variety ofparameters such as (1) the service provisioned to the UE—whether aninterruption of service provisioning would be acceptable; (2) thesubscription type of the subscriber—whether the subscriber is a premiumuser, a regular user, or a user of other privilege level; (3) thesubscription profile of the subscriber—whether the subscriber is aconsumer or an enterprise; (4) the availability of one or more networktransmission links needed for the handover; (5) the (guaranteed or besteffort based) bandwidth possible to be reserved on the one or morenetwork transmission links; and (6) the resource availability on thesource or target radio base station—whether there are enough processingresources, memory, database space to accommodate the moving andrebuilding of the VNFs. The determination may be different for differentVNFs providing services to the same UE.

Provisioning Services for a Roaming UE Using a SDN Controller

In one embodiment, one or both of the source and target radio basestations are implemented as a network device in a software definednetworking (SDN) system. The details of the network device in a SDNsystem are described in relation to FIGS. 18A-F. The SDN system containsone or more SDN controller (also referred to as a network controller andthe two terms are used interchangeably herein). A SDN controller managesthe network devices in the SDN system and it contains topologyinformation of the SDN system, thus the SDN controller may be utilizedto provide information about the network transmission links such as thebandwidth availability on the network transmission links and theresource availability on the source or target radio base station whenthe source or target radio base station is a network device of the SDNsystem.

FIG. 13 illustrates a network system for provisioning of services to aroaming UE using a SDN controller according to one embodiment of theinvention. FIG. 13 is similar to FIG. 2 thus only the difference betweenthe two figures are discussed. With regard to FIG. 13, a SDN controller1250 communicates with the VNF manager 230, and it may communicate withone or both of the source radio base station 210 and target radio basestation 220, when the one or both of the radio base stations are networkdevices of the SDN system managed by the SDN controller 1250.

The VNF manager 230 coordinates the handover of service off from VNF-1and VNF-2 at 240 and 245 to VNF-1 and VNF-2 at 250 and 255. During thehandover, the VNF manager 230 gets information for the handover from theSDN controller 1250 in one embodiment. For example, the SDN controller1250 may provide information about the available network transmissionlinks and their available bandwidths, and the SDN controller 1250 mayalso provide information about the resource availability of a radio basestation when it is implemented is a network device of the correspondingSDN system. In one embodiment, the UE 200 is also a network device ofthe corresponding SDN system, and the SDN controller 1250 may furtherprovide information about the service provisioned to the UE, thesubscription type and profile of the subscriber, and other informationspecific to the UE. With the information, the VNF manager 230 maydetermine which of the scenarios discussed above to use for differentVNFs.

In one embodiment, the VNF manager 230 and the SDN controller isintegrated in one electronic device, which is illustrated as thecontroller 1255, where the functionality of the VNF manager 230 and theSDN controller 1250 are integrated. While the integrated electronicdevice may also be called either VNF manager or SDN controller, theirfunctionalities include the ones of both the VNF manager and the SDNcontroller discussed herein.

FIG. 14 illustrates a network system for provisioning of services to aroaming UE using a SDN controller according to another embodiment of theinvention. FIG. 14 is similar to FIG. 3 thus only the difference betweenthe two figures are discussed. With regard to FIG. 14, a SDN controller1250 communicates with the VNF manager 230, and it may communicate withone or both of the source radio base station 210 and target radio basestation 220, when the one or both of the radio base stations are networkdevices of the SDN system managed by the SDN controller 1250.

In FIG. 14, the network interface 1480 may be a channel utilizing one ormore network transmission links such as a direct land-based connectionor microwave radio based transmission links between the two radio basestations 210 and 220. Radio base stations are typically hooked up to abackhaul network connecting them to the core network. Thus such networkinterface 1480 between two radio base stations may also be realized byrouting/switching via backhaul network connections or even byrouting/switching via a core network node. The network interface 1480may be based on routed packets connections or pre-established packettunnels using well-known layer 2 or layer 3 tunnel mechanisms. Theselection of such channel is based on the topology information receivedfrom the SDN controller 1250. Additionally, the realization byrouting/switching, the routed packet connections, or the pre-establishedpacket tunnels, is also performed based on information received from theSDN controller 1250. Furthermore, the determination of which of thesubset of the services is to be handed over to the target radio basestation 220 is based on a variety of factors, including the latencyrequirements of the services, the available network transmission linksand their available bandwidths, and these information may be retrievedfrom the SDN controller 1250. In other words, the VNF manager 230 mayrely on the SDN controller 1250 for information about the handover.Similar to FIG. 13, an integrated electronic device that is illustratedas the controller 1255.

FIG. 15 illustrates a network system for deploying a VNF on a targetradio base station using a SDN controller according to one embodiment ofthe invention. FIG. 15 is similar to FIG. 4 thus only the differencebetween the two figures are discussed. With regard to FIG. 15, a SDNcontroller 1250 communicates with the VNF manager 230, and it maycommunicate with one or both of the source radio base station 210 andtarget radio base station 220, when the one or both of the radio basestations are network devices of the SDN system managed by the SDNcontroller 1250. The VNF manager 230 performs the cloning of the VNF,and the VNF manager 230 may request one or more VNF at one time,depending on the available network transmission links and theiravailable bandwidths obtained from the SDN controller 1250. Similar toFIG. 13, an integrated electronic device that is illustrated as thecontroller 1255.

FIG. 16 illustrates a network system for deploying a VNF on a targetradio base station using a SDN controller according to anotherembodiment of the invention. FIG. 16 is similar to FIG. 5 thus only thedifference between the two figures are discussed. With regard to FIG.16, a SDN controller 1250 communicates with the VNF manager 230, and itmay communicate with one or both of the source radio base station 210and target radio base station 220, when the one or both of the radiobase stations are network devices of the SDN system managed by the SDNcontroller 1250. The database 260 and the library of communicationnetwork components 270 are the same or similar to the ones in FIG. 5.However, one or both of the database 260 and the library ofcommunication network components 270 may be in the SDN controller 1250in one embodiment. Similar to FIG. 13, an integrated electronic devicethat is illustrated as the controller 1255.

Flow Diagram for a VNF Manager Managing Service Delivery Using SDNController

FIG. 17 is a flow diagram illustrating a method of a VNF managermanaging service delivery using a SDN controller according to oneembodiment of the invention. The VNF manager may be the VNF manager 230or the controller 1255 discussed herein above, and the SDN controllermay be the SDN controller 1250 or the controller 1255. The VNF managermanages delivery of services to roaming UEs such as UE 200, which roamsfrom a radio coverage area of a source radio base station into a radiocoverage area of a target radio base station. The SDN controller managesa SDN system that includes at least one of the source base station andthe target radio base station as a network device of the SDN system.

At reference 1702, the VNF manager such as VNF manager 230 identifies atrigger condition for handing-over delivery of at least a subset of theservices from a radio interface of a source radio base station such asthe source radio base station 210 to a radio interface of a target radiobase station such as the target radio base station 220.

The trigger condition may be an indication received from the sourceradio base station or the SDN controller that the radio signal strengthof the radio interface of the source radio base station is fading for aUE. The SDN controller may provide such indication when the source radiobase station or the UE is implemented as a network device of thecorresponding SDN system. The indication may specify the subset of theservices to be handed over. The subset of the services may be selectedbased on factors such as the latency requirement of the services (themore sensitive a service to delay, the more likely the service needs tobe handed over), the bandwidth requirement of handing over theassociated VNF (the more bandwidth required, the less likely the VNFwill be handed over), the available bandwidth on network transmissionlinks (the more bandwidth being available, more VNFs/services are handedover).

At reference 1720, the VNF transfers the subset of the services to thetarget radio base station through a route based on information from theSDN controller. The information may include the topology information ofthe SDN system (including at least one of the source and target radiobase stations) such as the available network transmission links andtheir available bandwidths.

The transfer of the subset of the services may be through cloning theVNF(s) that delivers the subset of the services from the source radiobase station as discussed herein above in relation to FIGS. 2, 4, 6, 10,13, and 15. The cloned copy of the VNF(s) may be sent from the sourceradio base station to the VNF manager and then from the VNF manager tothe target radio base station; and the cloned copy of the VNF(s) mayalso be sent from the source radio base station directly to the targetradio base station. The route selection may differ accordingly in thesetwo approaches, and the information required to make the routingselection is retrieved from the SDN controller in one embodiment.

The transfer of the subset of the services may also be throughrebuilding the VNF(s) that delivers the subset of the services at thetarget radio base station as discussed herein above in relation to FIGS.2, 5, 6, 10, and 16. The building of the VNF(s) at the target radio basestation is based on information from the SDN controller in oneembodiment, the information including ones in the database 260 and/orthe library of communication network components 270. The route selectionin the building approach typically requires different amount ofbandwidths from connection to the source radio base station as the clonecopy is not required to be obtained from the source radio base station.On the other hand, since the building of the VNF at the target radiobase station is based on communication between the VNF manager and thetarget radio base station, the bandwidth requirement between the two islikely more.

The route selection in both cloning and the building the VNF(s) is basedon information in the SDN controller in one embodiment. Additionally, inone embodiment, the VNF manager causes the SDN controller to set up theroute for cloning or building the VNF(s). In the cloning approach, theSDN controller sets up the route between the source radio base stationand the target radio base station in one embodiment. In the rebuildingapproach, the SDN controller sets up a route between the VNF manager andthe target radio base station. The setting up the route includes the SDNcontroller causes flow table entries being installed in a network device(such as the source or target radio base station), so that packetsbelongs to a traffic flow (e.g. the traffic flow containing the clonecopy of the VNF(s) or the information regarding rebuilding of theVNF(s)) is to be routed as the SDN controller instructs. In the servicerebuilding approach, the VNF causes the SDN controller to set up theroute for the target radio base station to obtain constructioninformation on the subset of the services to deploy the at least VNF onthe target radio base station, and the construction information beingretrieved from a database.

It is to be noted that the VNF manager determines which scenariodiscussed in relation to FIG. 12 to apply for the subset of the servicesat step 1720. Based on the information obtained from the SDN controller,the VNF manager may determine all of the subset of the services utilizethe first or second scenario; alternatively, the VNF manager maydetermine the utilization of the first or second scenario on servicebasis because different services have different latency and/or bandwidthrequirement.

The selection of the scenario affects which route to be set up by theSDN controller. For example, if one or all of the subset of the servicesto be transferred takes the break-before-make approach (the secondscenario), the SDN controller will select a route based on an acceptableinterruption time for the one or the whole subset of the services. Theselected route may contain more network transmission links and/or theselected links may have more available bandwidths to accommodate the oneor the whole subset of the services (either through cloning or therebuilding of the VNF(s)) so that the interruption time for the one orthe whole subset of the services does not get over the acceptableinterruption time.

The selection of the scenario also affects the sequence of operations inthe service transfer. In one embodiment, when the first scenario isselected, the VNF manager instructs the target radio base station toprepare the target radio sources. The VNF manager then instructs thesource radio base station to inform the UE to hand over to the targetradio base station. Afterward, the VNF manager instructs the VNF on thesource radio base station to multicast the service delivery (1) overradio connection of the source radio base station to the UE, and (2)over network transmission link(s) to the target radio base station forservice delivery. Thus, the service delivering is duplicated at both thesource and target radio base stations during the transfer step 1720, andthe subset of the services is offered continuously by the source radiobase station prior to the subset of the services being offered by thetarget radio base station.

In one embodiment, when the second scenario is selected, the VNF manageralso instructs the target radio base station to prepare the target radiosources. The VNF manager then transfers the subset of the services tothe target radio base station. Additionally, the VNF manager instructsthe source radio base station to inform the UE to hand over to thetarget radio base station, and it causes removal of the source radioconnection to the UE. Thus, the service delivering is interrupted at thetransfer step 1720 in this embodiment.

At reference 1730, the VNF manager causes at least one VNF to bedeployed at the target radio base station, and the at least one VNF onthe target radio base station being adapted to offer the subset of theservices to the roaming UE. As discussed herein, the at least one VNFmay be deployed through either cloning or rebuilding. After the VNF iscloned or rebuilt at the target radio base station, the target radiobase station initializes and stars up the VNFs to offer the subset ofthe services to the roaming UE.

Additionally, in one embodiment, the VNF manager determines that one ormore additional services are to be transferred to the target radio basestation at reference 1740, and the determination causes the route beingupdated. The determination may be based on the roaming status of the UE,e.g., the UE is moving further away and causes more services to betransfer to the target radio base station. The updated route may be onthe same network transmission links but with different bandwidths beingutilized, and the updated route may be on different network/transmissionlinks

Furthermore, in one embodiment, the VNF manager updates the route basedon a number of VNFs within the set of VNFs remaining on the source radiobase station at reference 1750. At reference 1710, the trigger conditionmay be for a subset of the services offered by the set of VNFs hosted onthe source radio base station. Thus, some of the services (whichprovided by VNFs) may stay at the source radio base station after theoperations at references 1720 and 1730. When there are services and theassociated VNFs stay at the source radio base station for the UE, theroute may be updated for the VNFs to deliver services to the UE. Thereason is that the route used at reference 1720 is for transferring thesubset of the services thus the bandwidth may be different from (likelyhigher than) the ones required for the continuing delivery of servicethrough the source radio base station and the target radio base stationas illustrated in FIGS. 3 and 14. The operation of the remainingservices is discussed in more details in relation to step 750 of FIG. 7.

In one embodiment, at reference 1760, the VNF manager causes the removalof the at least one VNF on the source radio base station upon the atleast one VNF being deployed on the target radio base station. The VNFmanager instructs the source radio base station to delete the moved VNFonce that VNF (being cloned to or being rebuilt at the target radio basestation) is deployed.

It is to be noted that while the references 1740-1760 are illustrated inone order in FIG. 17. The illustration is only an embodiment of theinvention and the order may be different in another embodiment. Forexample, the removal of a VNF after it is deployed on the target radiobase station may happen first. Afterward, the route is updated based onthe number of VNFs within the set of VNFs remains on the source radiobase station (e.g., reducing the bandwidth for the route as less VNFsremain on the source radio base station); in alternative, the route maybe updated to transfer additional services (thus deploying additionalVNFs) to the target radio base station (e.g., increasing the bandwidthfor the route if the additional bandwidth becomes available to reducethe time to complete the transfer). Other operation sequences may beimplemented within the principles disclosed herein.

SDN and NFV Environment Utilizing Embodiments of the Invention

Embodiments of the invention may be utilized in a SDN and NFV networkcontaining network devices. FIG. 18A illustrates connectivity betweennetwork devices (NDs) within an exemplary network, as well as threeexemplary implementations of the NDs, according to some embodiments ofthe invention. FIG. 18A shows NDs 1800A-H, and their connectivity by wayof lines between A-B, B-C, C-D, D-E, E-F, F-G, and A-G, as well asbetween H and each of A, C, D, and G. These NDs are physical devices,and the connectivity between these NDs can be wireless or wired (oftenreferred to as a link). An additional line extending from NDs 1800A, E,and F illustrates that these NDs act as ingress and egress points forthe network (and thus, these NDs are sometimes referred to as edge NDs;while the other NDs may be called core NDs).

Two of the exemplary ND implementations in FIG. 18A are: 1) a specialpurpose network device 1802 that uses custom application—specificintegrated—circuits (ASICs) and a proprietary operating system (OS); and2) a general purpose network device 1804 that uses common off-the-shelf(COTS) processors and a standard OS.

The special purpose network device 1802 includes networking hardware1810 comprising compute resource(s) 1812 (which typically include a setof one or more processors), forwarding resource(s) 1814 (which typicallyinclude one or more ASICs and/or network processors), and physicalnetwork interfaces (NIs) 1816 (sometimes called physical ports), as wellas non-transitory machine readable storage media 1818 having storedtherein networking software 1820, including radio base station software1825. The radio base station software 1825 contains software modules toperform operations of the source or target radio base stations discussedherein above. A physical NI is hardware in a ND through which a networkconnection (e.g., wirelessly through a wireless network interfacecontroller (WNIC) or through plugging in a cable to a physical portconnected to a network interface controller (NIC)) is made, such asthose shown by the connectivity between NDs 1800A-H. During operation,the radio base station software 1825 may be executed by the networkinghardware 1810 to instantiate a radio base station software instance,which perform operations of a source or target radio base station asdiscussed herein above. The radio base station software instance andthat part of the networking hardware 1810 that executes that instance(be it hardware dedicated to that networking software instance and/ortime slices of hardware temporally shared by that networking softwareinstance with others of the networking software instance 1822), form aseparate virtual network element 1830A-R. Each of the virtual networkelement(s) (VNEs) 1830A-R includes a control communication andconfiguration module 1832A-R (sometimes referred to as a local controlmodule or control communication module) and forwarding table(s) 1834A-R,such that a given virtual network element (e.g., 1830A) includes thecontrol communication and configuration module (e.g., 1832A), a set ofone or more forwarding table(s) (e.g., 1834A), and that portion of thenetworking hardware 1810 that executes the virtual network element(e.g., 1830A).

The special purpose network device 1802 is often physically and/orlogically considered to include: 1) a ND control plane 1824 (sometimesreferred to as a control plane) comprising the compute resource(s) 1812that execute the control communication and configuration module(s)1832A-R; and 2) a ND forwarding plane 1826 (sometimes referred to as aforwarding plane, a data plane, or a media plane) comprising theforwarding resource(s) 1814 that utilize the forwarding table(s) 1834A-Rand the physical NIs 1816. By way of example, where the ND is a router(or is implementing routing functionality), the ND control plane 1824(the compute resource(s) 1812 executing the control communication andconfiguration module(s) 1832A-R) is typically responsible forparticipating in controlling how data (e.g., packets) is to be routed(e.g., the next hop for the data and the outgoing physical NI for thatdata) and storing that routing information in the forwarding table(s)1834A-R, and the ND forwarding plane 1826 is responsible for receivingthat data on the physical NIs 1816 and forwarding that data out theappropriate ones of the physical NIs 1816 based on the forwardingtable(s) 1834A-R.

FIG. 18B illustrates an exemplary way to implement a special purposenetwork device according to some embodiments of the invention. FIG. 18Bshows the special purpose network device including cards 1838 (typicallyhot pluggable). While in some embodiments the cards 1838 are of twotypes (one or more that operate as the ND forwarding plane 1826(sometimes called line cards), and one or more that operate to implementthe ND control plane 1824 (sometimes called control cards)), alternativeembodiments may combine functionality onto a single card and/or includeadditional card types (e.g., one additional type of card is called aservice card, resource card, or multi-application card). A service cardcan provide specialized processing (e.g., Layer 4 to Layer 7 services(e.g., firewall, Internet Protocol Security (IPsec), Secure SocketsLayer (SSL)/Transport Layer Security (TLS), Intrusion Detection System(IDS), peer-to-peer (P2P), Voice over IP (VoIP) Session BorderController, Mobile Wireless Gateways (Gateway General Packet RadioService (GPRS) Support Node (GGSN), Evolved Packet Core (EPC) Gateway)).By way of example, a service card may be used to terminate IPsec tunnelsand execute the attendant authentication and encryption algorithms.These cards are coupled together through one or more interconnectmechanisms illustrated as backplane 1836 (e.g., a first full meshcoupling the line cards and a second full mesh coupling all of thecards).

Returning to FIG. 18A, the general purpose network device 1804 includeshardware 1840 comprising a set of one or more processor(s) 1842 (whichare often COTS processors) and network interface controller(s) 1844(NICs; also known as network interface cards) (which include physicalNIs 1846), as well as non-transitory machine readable storage media 1848having stored therein software 1850, which may also contain the radiobase station software 1825. During operation, the processor(s) 1842execute the software 1850 to instantiate one or more sets of one or moreapplications 1864A-R. While one embodiment does not implementvirtualization, alternative embodiments may use different forms ofvirtualization. For example, in one such alternative embodiment thevirtualization layer 1854 represents the kernel of an operating system(or a shim executing on a base operating system) that allows for thecreation of multiple instances 1862A-R called software containers thatmay each be used to execute one (or more) of the sets of applications1864A-R; where the multiple software containers (also calledvirtualization engines, virtual private servers, or jails) are userspaces (typically a virtual memory space) that are separate from eachother and separate from the kernel space in which the operating systemis run; and where the set of applications running in a given user space,unless explicitly allowed, cannot access the memory of the otherprocesses. In another such alternative embodiment the virtualizationlayer 1854 represents a hypervisor (sometimes referred to as a virtualmachine monitor (VMM)) or a hypervisor executing on top of a hostoperating system, and each of the sets of applications 1864A-R is run ontop of a guest operating system within an instance 1862A-R called avirtual machine (which may in some cases be considered a tightlyisolated form of software container) that is run on top of thehypervisor - the guest operating system and application may not knowthey are running on a virtual machine as opposed to running on a “baremetal” host electronic device, or through para-virtualization theoperating system and/or application may be aware of the presence ofvirtualization for optimization purposes. In yet other alternativeembodiments, one, some or all of the applications are implemented asunikernel(s), which can be generated by compiling directly with anapplication only a limited set of libraries (e.g., from a libraryoperating system (LibOS) including drivers/libraries of OS services)that provide the particular OS services needed by the application. As aunikernel can be implemented to run directly on hardware 1840, directlyon a hypervisor (in which case the unikernel is sometimes described asrunning within a LibOS virtual machine), or in a software container,embodiments can be implemented fully with unikernels running directly ona hypervisor represented by virtualization layer 1854, unikernelsrunning within software containers represented by instances 1862A-R, oras a combination of unikernels and the above-described techniques (e.g.,unikernels and virtual machines both run directly on a hypervisor,unikernels and sets of applications that are run in different softwarecontainers).

The instantiation of the one or more sets of one or more applications1864A-R, as well as virtualization if implemented, are collectivelyreferred to as software instance(s) 1852. Each set of applications1864A-R, corresponding virtualization construct (e.g., instance 1862A-R)if implemented, and that part of the hardware 1840 that executes them(be it hardware dedicated to that execution and/or time slices ofhardware temporally shared), forms a separate virtual network element(s)1860A-R.

The virtual network element(s) 1860A-R perform similar functionality tothe virtual network element(s) 1830A-R - e g , similar to the controlcommunication and configuration module(s) 1832A and forwarding table(s)1834A (this virtualization of the hardware 1840 is sometimes referred toas network function virtualization (NFV)). Thus, NFV may be used toconsolidate many network equipment types onto industry standard highvolume server hardware, physical switches, and physical storage, whichcould be located in Data centers, NDs, and customer premise equipment(CPE). While embodiments of the invention are illustrated with eachinstance 1862A-R corresponding to one VNE 1860A-R, alternativeembodiments may implement this correspondence at a finer levelgranularity (e.g., line card virtual machines virtualize line cards,control card virtual machine virtualize control cards, etc.); it shouldbe understood that the techniques described herein with reference to acorrespondence of instances 1862A-R to VNEs also apply to embodimentswhere such a finer level of granularity and/or unikernels are used.

In certain embodiments, the virtualization layer 1854 includes a virtualswitch that provides similar forwarding services as a physical Ethernetswitch. Specifically, this virtual switch forwards traffic betweensoftware containers 1862A-R and the NIC(s) 1844, as well as optionallybetween the software containers 1862A-R; in addition, this virtualswitch may enforce network isolation between the VNEs 1860A-R that bypolicy are not permitted to communicate with each other (e.g., byhonoring virtual local area networks (VLANs)).

The third exemplary ND implementation in FIG. 18A is a hybrid networkdevice 1806, which includes both custom ASICs/proprietary OS and COTSprocessors/standard OS in a single ND or a single card within an ND. Incertain embodiments of such a hybrid network device, a platform VM(i.e., a VM that that implements the functionality of the specialpurpose network device 1802) could provide for para-virtualization tothe networking hardware present in the hybrid network device 1806.

Regardless of the above exemplary implementations of an ND, when asingle one of multiple VNEs implemented by an ND is being considered(e.g., only one of the VNEs is part of a given virtual network) or whereonly a single VNE is currently being implemented by an ND, the shortenedterm network element (NE) is sometimes used to refer to that VNE. Alsoin all of the above exemplary implementations, each of the VNEs (e.g.,VNE(s) 1830A-R, VNEs 1860A-R, and those in the hybrid network device1806) receives data on the physical NIs (e.g., 1816, 1846) and forwardsthat data out the appropriate ones of the physical NIs (e.g., 1816,1846). For example, a VNE implementing IP router functionality forwardsIP packets on the basis of some of the IP header information in the IPpacket; where IP header information includes source IP address,destination IP address, source port, destination port (where “sourceport” and “destination port” refer herein to protocol ports, as opposedto physical ports of a ND), transport protocol (e.g., user datagramprotocol (UDP), Transmission Control Protocol (TCP), and differentiatedservices code point (DSCP) values.

FIG. 18C illustrates various exemplary ways in which VNEs may be coupledaccording to some embodiments of the invention. FIG. 18C shows VNEs1870A.1-1870A.P (and optionally VNEs 1870A.Q-1870A.R) implemented in ND1800A and VNE 1870H.1 in ND 1800H. In FIG. 18C, VNEs 1870A.1-P areseparate from each other in the sense that they can receive packets fromoutside ND 1800A and forward packets outside of ND 1800A; VNE 1870A.1 iscoupled with VNE 1870H.1, and thus they communicate packets betweentheir respective NDs; VNE 1870A.2-1870A.3 may optionally forward packetsbetween themselves without forwarding them outside of the ND 1800A; andVNE 1870A.P may optionally be the first in a chain of VNEs that includesVNE 1870A.Q followed by VNE 1870A.R (this is sometimes referred to asdynamic service chaining, where each of the VNEs in the series of VNEsprovides a different service—e.g., one or more layer 4-7 networkservices). While FIG. 18C illustrates various exemplary relationshipsbetween the VNEs, alternative embodiments may support otherrelationships (e.g., more/fewer VNEs, more/fewer dynamic service chains,multiple different dynamic service chains with some common VNEs and somedifferent VNEs).

The NDs of FIG. 18A, for example, may form part of the Internet or aprivate network; and other electronic devices (not shown; such as enduser devices including workstations, laptops, netbooks, tablets, palmtops, mobile phones, smartphones, multimedia phones, Voice Over InternetProtocol (VOIP) phones, terminals, portable media players, GPS units,wearable devices, gaming systems, set-top boxes, Internet enabledhousehold appliances) may be coupled to the network (directly or throughother networks such as access networks) to communicate over the network(e.g., the Internet or virtual private networks (VPNs) overlaid on(e.g., tunneled through) the Internet) with each other (directly orthrough servers) and/or access content and/or services. Such contentand/or services are typically provided by one or more servers (notshown) belonging to a service/content provider or one or more end userdevices (not shown) participating in a peer-to-peer (P2P) service, andmay include, for example, public webpages (e.g., free content, storefronts, search services), private webpages (e.g., username/passwordaccessed webpages providing email services), and/or corporate networksover VPNs. For instance, end user devices may be coupled (e.g., throughcustomer premise equipment coupled to an access network (wired orwirelessly)) to edge NDs, which are coupled (e.g., through one or morecore NDs) to other edge NDs, which are coupled to electronic devicesacting as servers. However, through compute and storage virtualization,one or more of the electronic devices operating as the NDs in FIG. 18Amay also host one or more such servers (e.g., in the case of the generalpurpose network device 1804, one or more of the virtual machines 1862A-Rmay operate as servers; the same would be true for the hybrid networkdevice 1806; in the case of the special purpose network device 1802, oneor more such servers could also be run on a hypervisor executed by thecompute resource(s) 1812); in which case the servers are said to beco-located with the VNEs of that ND.

A virtual network is a logical abstraction of a physical network (suchas that in FIG. 18A) that provides network services (e.g., L2 and/or L3services). A virtual network can be implemented as an overlay network(sometimes referred to as a network virtualization overlay) thatprovides network services (e.g., layer 2 (L2, data link layer) and/orlayer 3 (L3, network layer) services) over an underlay network (e.g., anL3 network, such as an Internet Protocol (IP) network that uses tunnels(e.g., generic routing encapsulation (GRE), layer 2 tunneling protocol(L2TP), IPSec) to create the overlay network).

A network virtualization edge (NVE) sits at the edge of the underlaynetwork and participates in implementing the network virtualization; thenetwork-facing side of the NVE uses the underlay network to tunnelframes to and from other NVEs; the outward-facing side of the NVE sendsand receives data to and from systems outside the network. A virtualnetwork instance (VNI) is a specific instance of a virtual network on aNVE (e.g., a NE/VNE on an ND, a part of a NE/VNE on a ND where thatNE/VNE is divided into multiple VNEs through emulation); one or moreVNIs can be instantiated on an NVE (e.g., as different VNEs on an ND). Avirtual access point (VAP) is a logical connection point on the NVE forconnecting external systems to a virtual network; a VAP can be physicalor virtual ports identified through logical interface identifiers (e.g.,a VLAN ID).

Examples of network services include: 1) an Ethernet LAN emulationservice (an Ethernet-based multipoint service similar to an InternetEngineering Task Force (IETF) Multiprotocol Label Switching (MPLS) orEthernet VPN (EVPN) service) in which external systems areinterconnected across the network by a LAN environment over the underlaynetwork (e.g., an NVE provides separate L2 VNIs (virtual switchinginstances) for different such virtual networks, and L3 (e.g., IP/MPLS)tunneling encapsulation across the underlay network); and 2) avirtualized IP forwarding service (similar to IETF IP VPN (e.g., BorderGateway Protocol (BGP)/MPLS IPVPN) from a service definitionperspective) in which external systems are interconnected across thenetwork by an L3 environment over the underlay network (e.g., an NVEprovides separate L3 VNIs (forwarding and routing instances) fordifferent such virtual networks, and L3 (e.g., IP/MPLS) tunnelingencapsulation across the underlay network)). Network services may alsoinclude quality of service capabilities (e.g., traffic classificationmarking, traffic conditioning and scheduling), security capabilities(e.g., filters to protect customer premises from network—originatedattacks, to avoid malformed route announcements), and managementcapabilities (e.g., full detection and processing).

FIG. 18D illustrates a network with a single network element on each ofthe NDs of FIG. 18A. Specifically, FIG. 18D illustrates network elements(NEs) 1870A-H with the same connectivity as the NDs 1800A-H of FIG. 18Awith a centralized approach for maintaining reachability and forwardinginformation (also called network control), according to some embodimentsof the invention.

FIG. 18D illustrates that a centralized approach 1874 (also known assoftware defined networking (SDN)) that decouples the system that makesdecisions about where traffic is sent from the underlying systems thatforwards traffic to the selected destination. The illustratedcentralized approach 1874 has the responsibility for the generation ofreachability and forwarding information in a centralized control plane1876 (sometimes referred to as a SDN control module, controller, networkcontroller, OpenFlow controller, SDN controller, control plane node,network virtualization authority, or management control entity), andthus the process of neighbor discovery and topology discovery iscentralized. The centralized control plane 1876 has a south boundinterface 1882 with a data plane 1880 (sometime referred to theinfrastructure layer, network forwarding plane, or forwarding plane(which should not be confused with a ND forwarding plane)) that includesthe NEs 1870A-H (sometimes referred to as switches, forwarding elements,data plane elements, or nodes). The centralized control plane 1876includes a network controller 1878, which includes a centralizedreachability and forwarding information module 1879 that determines thereachability within the network and distributes the forwardinginformation to the NEs 1870A-H of the data plane 1880 over the southbound interface 1882 (which may use the OpenFlow protocol). Thecentralized reachability and forwarding information module 1879 containsthe VNF manager 1875. The VNF manager 1875 within the network controller1878 is one embodiment of the integrated controller 1255 discussedherein above in relation to FIGS. 13-16.

The network intelligence is centralized in the centralized control plane1876 executing on electronic devices that are typically separate fromthe NDs. For example, where the special purpose network device 1802 isused in the data plane 1880, each of the control communication andconfiguration module(s) 1832A-R of the ND control plane 1824 typicallyinclude a control agent that provides the VNE side of the south boundinterface 1882. In this case, the ND control plane 1824 (the computeresource(s) 1812 executing the control communication and configurationmodule(s) 1832A-R) performs its responsibility for participating incontrolling how data (e.g., packets) is to be routed (e.g., the next hopfor the data and the outgoing physical NI for that data) through thecontrol agent communicating with the centralized control plane 1876 toreceive the forwarding information (and in some cases, the reachabilityinformation) from the centralized reachability and forwardinginformation module 1879 (it should be understood that in someembodiments of the invention, the control communication andconfiguration module(s) 1832A-R, in addition to communicating with thecentralized control plane 1876, may also play some role in determiningreachability and/or calculating forwarding information—albeit less sothan in the case of a distributed approach; such embodiments aregenerally considered to fall under the centralized approach 1874, butmay also be considered a hybrid approach).

While the above example uses the special purpose network device 1802,the same centralized approach 1874 can be implemented with the generalpurpose network device 1804 (e.g., each of the VNE 1860A-R performs itsresponsibility for controlling how data (e.g., packets) is to be routed(e.g., the next hop for the data and the outgoing physical NI for thatdata) by communicating with the centralized control plane 1876 toreceive the forwarding information (and in some cases, the reachabilityinformation) from the centralized reachability and forwardinginformation module 1879; it should be understood that in someembodiments of the invention, the VNEs 1860A-R, in addition tocommunicating with the centralized control plane 1876, may also playsome role in determining reachability and/or calculating forwardinginformation—albeit less so than in the case of a distributed approach)and the hybrid network device 1806. In fact, the use of SDN techniquescan enhance the NFV techniques typically used in the general purposenetwork device 1804 or hybrid network device 1806 implementations as NFVis able to support SDN by providing an infrastructure upon which the SDNsoftware can be run, and NFV and SDN both aim to make use of commodityserver hardware and physical switches.

FIG. 18D also shows that the centralized control plane 1876 has a northbound interface 1884 to an application layer 1886, in which residesapplication(s) 1888. The centralized control plane 1876 has the abilityto form virtual networks 1892 (sometimes referred to as a logicalforwarding plane, network services, or overlay networks (with the NEs1870A-H of the data plane 1880 being the underlay network)) for theapplication(s) 1888. Thus, the centralized control plane 1876 maintainsa global view of all NDs and configured NEs/VNEs, and it maps thevirtual networks to the underlying NDs efficiently (includingmaintaining these mappings as the physical network changes eitherthrough hardware (ND, link, or ND component) failure, addition, orremoval).

While FIG. 18D illustrates the simple case where each of the NDs 1800A-Himplements a single NE 1870A-H, it should be understood that the networkcontrol approaches described with reference to FIG. 18D also work fornetworks where one or more of the NDs 1800A-H implement multiple VNEs(e.g., VNEs 1830A-R, VNEs 1860A-R, those in the hybrid network device1806). Alternatively or in addition, the network controller 1878 mayalso emulate the implementation of multiple VNEs in a single ND.Specifically, instead of (or in addition to) implementing multiple VNEsin a single ND, the network controller 1878 may present theimplementation of a VNE/NE in a single ND as multiple VNEs in thevirtual networks 1892 (all in the same one of the virtual network(s)1892, each in different ones of the virtual network(s) 1892, or somecombination). For example, the network controller 1878 may cause an NDto implement a single VNE (a NE) in the underlay network, and thenlogically divide up the resources of that NE within the centralizedcontrol plane 1876 to present different VNEs in the virtual network(s)1892 (where these different VNEs in the overlay networks are sharing theresources of the single VNE/NE implementation on the ND in the underlaynetwork).

On the other hand, FIGS. 18E and 18F respectively illustrate exemplaryabstractions of NEs and VNEs that the network controller 1878 maypresent as part of different ones of the virtual networks 1892. FIG. 18Eillustrates the simple case of where each of the NDs 1800A-H implementsa single NE 1870A-H (see FIG. 18D), but the centralized control plane1876 has abstracted multiple of the NEs in different NDs (the NEs1870A-C and G-H) into (to represent) a single NE 18701 in one of thevirtual network(s) 1892 of FIG. 18D, according to some embodiments ofthe invention. FIG. 18E shows that in this virtual network, the NE 18701is coupled to NE 1870D and 1870F, which are both still coupled to NE1870E.

FIG. 18F illustrates a case where multiple VNEs (VNE 1870A.1 and VNE1870H.1) are implemented on different NDs (ND 1800A and ND 1800H) andare coupled to each other, and where the centralized control plane 1876has abstracted these multiple VNEs such that they appear as a single VNE1870T within one of the virtual networks 1892 of FIG. 18D, according tosome embodiments of the invention. Thus, the abstraction of a NE or VNEcan span multiple NDs.

While some embodiments of the invention implement the centralizedcontrol plane 1876 as a single entity (e.g., a single instance ofsoftware running on a single electronic device), alternative embodimentsmay spread the functionality across multiple entities for redundancyand/or scalability purposes (e.g., multiple instances of softwarerunning on different electronic devices).

Similar to the network device implementations, the electronic device(s)running the centralized control plane 1876, and thus the networkcontroller 1878 including the centralized reachability and forwardinginformation module 1879, may be implemented a variety of ways (e.g., aspecial purpose device, a general-purpose (e.g., COTS) device, or hybriddevice). These electronic device(s) would similarly include computeresource(s), a set or one or more physical NICs, and a non-transitorymachine-readable storage medium having stored thereon the centralizedcontrol plane software. For instance, FIG. 19 illustrates, a generalpurpose control plane device 1904 including hardware 1940 comprising aset of one or more processor(s) 1942 (which are often COTS processors)and network interface controller(s) 1944 (NICs; also known as networkinterface cards) (which include physical NIs 1946), as well asnon-transitory machine readable storage media 1948 having stored thereincentralized control plane (CCP) software 1950. The CCP software 1950includes the VNF manager 1875 discussed herein above.

In embodiments that use compute virtualization, the processor(s) 1942typically execute software to instantiate a virtualization layer 1954and software container(s) 1962A-R (e.g., with operating system-levelvirtualization, the virtualization layer 1954 represents the kernel ofan operating system (or a shim executing on a base operating system)that allows for the creation of multiple software containers 1962A-R(representing separate user space instances and also calledvirtualization engines, virtual private servers, or jails) that may eachbe used to execute a set of one or more applications; with fullvirtualization, the virtualization layer 1954 represents a hypervisor(sometimes referred to as a virtual machine monitor (VMM)) or ahypervisor executing on top of a host operating system, and the softwarecontainers 1962A-R each represent a tightly isolated form of softwarecontainer called a virtual machine that is run by the hypervisor and mayinclude a guest operating system; with para-virtualization, an operatingsystem or application running with a virtual machine may be aware of thepresence of virtualization for optimization purposes). Again, inembodiments where compute virtualization is used, during operation aninstance of the CCP software 1950 (illustrated as CCP instance 1976A) isexecuted within the software container 1962A on the virtualization layer1954. In embodiments where compute virtualization is not used, the CCPinstance 1976A on top of a host operating system is executed on the“bare metal” general purpose control plane device 1904. Theinstantiation of the CCP instance 1976A, as well as the virtualizationlayer 1954 and software containers 1962A-R if implemented, arecollectively referred to as software instance(s) 1952.

In some embodiments, the CCP instance 1976A includes a networkcontroller instance 1978. The network controller instance 1978 includesa centralized reachability and forwarding information module instance1979 (which is a middleware layer providing the context of the networkcontroller 1878 to the operating system and communicating with thevarious NEs), and an CCP application layer 1980 (sometimes referred toas an application layer) over the middleware layer (providing theintelligence required for various network operations such as protocols,network situational awareness, and user-interfaces). A VNF managerinstance 1975 is included in the CCP application layer 1980 in oneembodiment. At a more abstract level, this CCP application layer 1980within the centralized control plane 1876 works with virtual networkview(s) (logical view(s) of the network) and the middleware layerprovides the conversion from the virtual networks to the physical view.

The centralized control plane 1876 transmits relevant messages to thedata plane 1880 based on CCP application layer 1980 calculations andmiddleware layer mapping for each flow. A flow may be defined as a setof packets whose headers match a given pattern of bits; in this sense,traditional IP forwarding is also flow-based forwarding where the flowsare defined by the destination IP address for example; however, in otherimplementations, the given pattern of bits used for a flow definitionmay include more fields (e.g., 10 or more) in the packet headers.Different NDs/NEs/VNEs of the data plane 1880 may receive differentmessages, and thus different forwarding information. The data plane 1880processes these messages and programs the appropriate flow informationand corresponding actions in the forwarding tables (sometime referred toas flow tables) of the appropriate NE/VNEs, and then the NEs/VNEs mapincoming packets to flows represented in the forwarding tables andforward packets based on the matches in the forwarding tables.

Standards such as OpenFlow define the protocols used for the messages,as well as a model for processing the packets. The model for processingpackets includes header parsing, packet classification, and makingforwarding decisions. Header parsing describes how to interpret a packetbased upon a well-known set of protocols. Some protocol fields are usedto build a match structure (or key) that will be used in packetclassification (e.g., a first key field could be a source media accesscontrol (MAC) address, and a second key field could be a destination MACaddress).

Packet classification involves executing a lookup in memory to classifythe packet by determining which entry (also referred to as a forwardingtable entry or flow entry) in the forwarding tables best matches thepacket based upon the match structure, or key, of the forwarding tableentries. It is possible that many flows represented in the forwardingtable entries can correspond/match to a packet; in this case the systemis typically configured to determine one forwarding table entry from themany according to a defined scheme (e.g., selecting a first forwardingtable entry that is matched). Forwarding table entries include both aspecific set of match criteria (a set of values or wildcards, or anindication of what portions of a packet should be compared to aparticular value/values/wildcards, as defined by the matchingcapabilities—for specific fields in the packet header, or for some otherpacket content), and a set of one or more actions for the data plane totake on receiving a matching packet. For example, an action may be topush a header onto the packet, for the packet using a particular port,flood the packet, or simply drop the packet. Thus, a forwarding tableentry for IPv4/IPv6 packets with a particular transmission controlprotocol (TCP) destination port could contain an action specifying thatthese packets should be dropped.

Making forwarding decisions and performing actions occurs, based uponthe forwarding table entry identified during packet classification, byexecuting the set of actions identified in the matched forwarding tableentry on the packet.

However, when an unknown packet (for example, a “missed packet” or a“match-miss” as used in OpenFlow parlance) arrives at the data plane1880, the packet (or a subset of the packet header and content) istypically forwarded to the centralized control plane 1876. Thecentralized control plane 1876 will then program forwarding tableentries into the data plane 1880 to accommodate packets belonging to theflow of the unknown packet. Once a specific forwarding table entry hasbeen programmed into the data plane 1880 by the centralized controlplane 1876, the next packet with matching credentials will match thatforwarding table entry and take the set of actions associated with thatmatched entry.

A network interface (NI) may be physical or virtual; and in the contextof IP, an interface address is an IP address assigned to a NI, be it aphysical NI or virtual NI. A virtual NI may be associated with aphysical NI, with another virtual interface, or stand on its own (e.g.,a loopback interface, a point-to-point protocol interface). A NI(physical or virtual) may be numbered (a NI with an IP address) orunnumbered (a NI without an IP address). A loopback interface (and itsloopback address) is a specific type of virtual NI (and IP address) of aNE/VNE (physical or virtual) often used for management purposes; wheresuch an IP address is referred to as the nodal loopback address. The IPaddress(es) assigned to the NI(s) of a ND are referred to as IPaddresses of that ND; at a more granular level, the IP address(es)assigned to NI(s) assigned to a NE/VNE implemented on a ND can bereferred to as IP addresses of that NE/VNE.

Each VNE (e.g., a virtual router, a virtual bridge (which may act as avirtual switch instance in a Virtual Private LAN Service (VPLS) istypically independently administrable. For example, in the case ofmultiple virtual routers, each of the virtual routers may share systemresources but is separate from the other virtual routers regarding itsmanagement domain, AAA (authentication, authorization, and accounting)name space, IP address, and routing database(s). Multiple VNEs may beemployed in an edge ND to provide direct network access and/or differentclasses of services for subscribers of service and/or content providers.

Within certain NDs, “interfaces” that are independent of physical NIsmay be configured as part of the VNEs to provide higher-layer protocoland service information (e.g., Layer 3 addressing). The subscriberrecords in the AAA server identify, in addition to the other subscriberconfiguration requirements, to which context (e.g., which of theVNEs/NEs) the corresponding subscribers should be bound within the ND.As used herein, a binding forms an association between a physical entity(e.g., physical NI, channel) or a logical entity (e.g., circuit such asa subscriber circuit or logical circuit (a set of one or more subscribercircuits)) and a context's interface over which network protocols (e.g.,routing protocols, bridging protocols) are configured for that context.Subscriber data flows on the physical entity when some higher-layerprotocol interface is configured and associated with that physicalentity.

Some NDs include functionality for authentication, authorization, andaccounting (AAA) protocols (e.g., RADIUS (Remote Authentication Dial-InUser Service), Diameter, and/or TACACS+ (Terminal Access ControllerAccess Control System Plus). AAA can be provided through a client/servermodel, where the AAA client is implemented on a ND and the AAA servercan be implemented either locally on the ND or on a remote electronicdevice coupled with the ND. Authentication is the process of identifyingand verifying a subscriber. For instance, a subscriber might beidentified by a combination of a username and a password or through aunique key. Authorization determines what a subscriber can do afterbeing authenticated, such as gaining access to certain electronic deviceinformation resources (e.g., through the use of access controlpolicies). Accounting is recording user activity. By way of a summaryexample, end user devices may be coupled (e.g., through an accessnetwork) through an edge ND (supporting AAA processing) coupled to coreNDs coupled to electronic devices implementing servers ofservice/content providers. AAA processing is performed to identify for asubscriber the subscriber record stored in the AAA server for thatsubscriber. A subscriber record includes a set of attributes (e.g.,subscriber name, password, authentication information, access controlinformation, rate-limiting information, policing information) usedduring processing of that subscriber's traffic.

The operations of the flow diagrams of FIGS. 6-9 and 17 are describedwith reference to the exemplary embodiment of FIGS. 10-11, 18A-F, and 9.However, it should be understood that the operations of flow diagramscan be performed by embodiments of the invention other than thosediscussed with reference to the exemplary embodiment of FIGS. 10-11,18A-F, and 19, and the exemplary embodiment of FIGS. 10-11, 18A-F, and19 can perform operations different than those discussed with referenceto the flow diagrams of FIGS. 6-9 and 17.

While the flow diagrams in the figures herein above show a particularorder of operations performed by certain embodiments of the invention,it should be understood that such order is exemplary (e.g., alternativeembodiments may perform the operations in a different order, combinecertain operations, overlap certain operations, etc.).

Different embodiments of the invention may be implemented usingdifferent combinations of software, firmware, and/or hardware. Thus, thetechniques shown in the figures can be implemented using code and datastored and executed on one or more electronic devices (e.g., an endsystem, a network device). Such electronic devices store and communicate(internally and/or with other electronic devices over a network) codeand data using computer-readable media, such as non-transitorycomputer-readable storage media (e.g., magnetic disks; optical disks;random access memory; read only memory; flash memory devices;phase-change memory) and transitory computer-readable transmission media(e.g., electrical, optical, acoustical or other form of propagatedsignals—such as carrier waves, infrared signals, digital signals). Inaddition, such electronic devices typically include a set of one or moreprocessors coupled to one or more other components, such as one or morestorage devices (non-transitory machine-readable storage media), userinput/output devices (e.g., a keyboard, a touchscreen, and/or adisplay), and network connections. The coupling of the set of processorsand other components is typically through one or more busses and bridges(also termed as bus controllers). Thus, the storage device of a givenelectronic device typically stores code and/or data for execution on theset of one or more processors of that electronic device.

While the invention has been described in terms of several embodiments,those skilled in the art will recognize that the invention is notlimited to the embodiments described, can be practiced with modificationand alteration within the spirit and scope of the appended claims. Thedescription is thus to be regarded as illustrative instead of limiting.

1. A method implemented in a virtual network function, (VNF) manager fordelivering of services to a roaming user equipment (UE), the servicesbeing offered by a set of VNFs hosted on a source radio base station,and being delivered to the roaming UE via a radio interface of thesource radio base station, wherein the roaming UE is to roam from aradio coverage area of the source radio base station into a radiocoverage area of a target radio base station, the method comprising:identifying a trigger condition for handing-over delivery of at least asubset of the services from the radio interface of the source radio basestation to a radio interface of the target radio base station;transferring the subset of the services to the target radio base stationthrough a route based on information from a software-defined networking(SDN) controller of a SDN system that includes the source radio basestation and the target radio base station; and causing at least one VNFto be deployed on the target radio base station, the at least one VNF onthe target radio base station being adapted to offer the subset of theservices to the roaming UE.
 2. The method of claim 1, wherein thetransferring the subset of the services to the target radio base stationcomprises: causing the SDN controller to set up the route from thesource radio base station to the target radio base station based on abandwidth required to transfer a clone of the at least one VNF from thesource radio base station to the target radio base station.
 3. Themethod of claim 2, wherein the subset of the services is interruptedprior to the subset of the services being offered by the target radiobase station and the bandwidth required is based on an acceptableinterruption time for the at least the subset of the services.
 4. Themethod of claim 1, wherein the subset of the services is offeredcontinuously by the source radio base station prior to the subset of theservice being offered by the target radio base station.
 5. The method ofclaim 1, wherein the transferring the subset of the services to thetarget radio base station (220) comprises: causing the SDN controller toset up the route for the target radio base station to obtainconstruction information on the subset of the services to deploy the atleast VNF on the target radio base station, and the constructioninformation being retrieved from a database.
 6. The method of claim 1,further comprising: updating the route based on the information from theSDN controller upon determining that additional services are to betransferred to the target radio base station.
 7. The method of claim 1,further comprising: updating the route based on a number of VNFs withinthe set of VNFs remaining on the source radio base station.
 8. Themethod of claim 1, further comprising: removing the at least one VNF onthe source radio base station upon the at least one VNF being deployedon the target radio base station.
 9. The method of claim 1, wherein theSDN controller is implemented in a same electronic device with the VNFmanager.
 10. A virtual network function, (VNF) manager for delivering ofservices to a roaming user equipment (UE), the services being to beoffered by a set of VNFs hosted on a source radio base station, andbeing to be delivered to the roaming UE via a radio interface of thesource radio base station, wherein the roaming UE is to roam from aradio coverage area of the source radio base station into a radiocoverage area of a target radio base station, the VNF managercomprising: a processor and a non-transitory machine-readable storagemedium the coupled to the processor, the non-transitory machine-readablestorage medium containing instructions, which when executed by theprocessor, cause the VNF manager to: identify a trigger condition forhanding-over delivery of at least a subset of the services from theradio interface of the source radio base station to a radio interface ofthe target radio base station, transfer the subset of the services tothe target radio base station through a route based on information froma software-defined networking (SDN) controller of a SDN system thatincludes the source radio base station and the target radio basestation, and cause at least one VNF to be deployed on the target radiobase station, the at least one VNF on the target radio base stationbeing adapted to offer the subset of the services to the roaming UE. 11.The VNF manager of claim 10, wherein the transfer of the subset of theservices to the target radio base station is to: cause the SDNcontroller to set up the route from the source radio base station to thetarget radio base station based on a bandwidth required to transfer aclone of the at least one VNF from the source radio base station to thetarget radio base station.
 12. The VNF manager of claim 10, wherein thetransfer of the subset of the services to the target radio base stationis to: cause the SDN controller to set up the route for the target radiobase station to obtain construction information on the subset of theservices to deploy the at least VNF on the target radio base station,and the construction information being retrieved from a database. 13.The VNF manager of claim 10, where the VNF manager is further to: updatethe route based on the information from the SDN controller upondetermining that additional services are to be transferred to the targetradio base station.
 14. The VNF manager of claim 10, wherein the SDNcontroller is implemented in a same electronic device with the VNFmanager.
 15. A non-transitory machine-readable medium havinginstructions stored therein, which when executed by a processor, causethe processor to perform operations in a virtual network function, (VNF)manager for delivering of services to a roaming user equipment (UE), theservices being offered by a set of VNFs hosted on a source radio basestation, and being delivered to the roaming UE via a radio interface ofthe source radio base station, wherein the roaming UE is to roam from aradio coverage area of the source radio base station into a radiocoverage area of a target radio base station, the operations comprising:identifying a trigger condition for handing-over delivery of at least asubset of the services from the radio interface of the source radio basestation to a radio interface of the target radio base station;transferring the subset of the services to the target radio base stationthrough a route based on information from a software-defined networking(SDN) controller of a SDN system that includes the source radio basestation and the target radio base station; and causing at least one VNFto be deployed on the target radio base station, the at least one VNF onthe target radio base station being adapted to offer the subset of theservices to the roaming UE.
 16. The non-transitory machine-readablemedium of claim 15, wherein the transferring the subset of the servicesto the target radio base station comprises: causing the SDN controllerto set up the route from the source radio base station to the targetradio base station based on a bandwidth required to transfer a clone ofthe at least one VNF from the source radio base station to the targetradio base station.
 17. The non-transitory machine-readable medium ofclaim 16, wherein the subset of the services is interrupted prior to thesubset of the services being offered by the target radio base stationand the bandwidth required is based on an acceptable interruption timefor the at least the subset of the services.
 18. The non-transitorymachine-readable medium of claim 15, wherein the operations furthercomprise: updating the route based on the information from the SDNcontroller upon determining that additional services are to betransferred to the target radio base station.
 19. The non-transitorymachine-readable medium of claim 15, wherein the operations furthercomprise: updating the route based on a number of VNFs within the set ofVNFs remaining on the source radio base station.
 20. The non-transitorymachine-readable medium of claim 15, wherein the operations furthercomprise: removing the at least one VNF on the source radio base stationupon the at least one VNF being deployed on the target radio basestation.